US20010001989A1 - Microelectronic connections with liquid conductive elements - Google Patents
Microelectronic connections with liquid conductive elements Download PDFInfo
- Publication number
- US20010001989A1 US20010001989A1 US09/757,897 US75789701A US2001001989A1 US 20010001989 A1 US20010001989 A1 US 20010001989A1 US 75789701 A US75789701 A US 75789701A US 2001001989 A1 US2001001989 A1 US 2001001989A1
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- United States
- Prior art keywords
- masses
- microelectronic
- conductive
- microelectronic element
- fusible
- Prior art date
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- H01L2924/15174—Fan-out arrangement of the internal vias in different layers of the multilayer substrate
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- H01L2924/1531—Connection portion the connection portion being formed only on the surface of the substrate opposite to the die mounting surface
- H01L2924/15311—Connection portion the connection portion being formed only on the surface of the substrate opposite to the die mounting surface being a ball array, e.g. BGA
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- H01L2924/15—Details of package parts other than the semiconductor or other solid state devices to be connected
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- H01L2924/191—Disposition
- H01L2924/19101—Disposition of discrete passive components
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T29/00—Metal working
- Y10T29/49—Method of mechanical manufacture
- Y10T29/49002—Electrical device making
- Y10T29/49117—Conductor or circuit manufacturing
- Y10T29/49124—On flat or curved insulated base, e.g., printed circuit, etc.
- Y10T29/49126—Assembling bases
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T29/00—Metal working
- Y10T29/49—Method of mechanical manufacture
- Y10T29/49002—Electrical device making
- Y10T29/49117—Conductor or circuit manufacturing
- Y10T29/49124—On flat or curved insulated base, e.g., printed circuit, etc.
- Y10T29/4913—Assembling to base an electrical component, e.g., capacitor, etc.
- Y10T29/49133—Assembling to base an electrical component, e.g., capacitor, etc. with component orienting
- Y10T29/49135—Assembling to base an electrical component, e.g., capacitor, etc. with component orienting and shaping, e.g., cutting or bending, etc.
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T29/00—Metal working
- Y10T29/49—Method of mechanical manufacture
- Y10T29/49002—Electrical device making
- Y10T29/49117—Conductor or circuit manufacturing
- Y10T29/49124—On flat or curved insulated base, e.g., printed circuit, etc.
- Y10T29/4913—Assembling to base an electrical component, e.g., capacitor, etc.
- Y10T29/49144—Assembling to base an electrical component, e.g., capacitor, etc. by metal fusion
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T29/00—Metal working
- Y10T29/49—Method of mechanical manufacture
- Y10T29/49002—Electrical device making
- Y10T29/49117—Conductor or circuit manufacturing
- Y10T29/49124—On flat or curved insulated base, e.g., printed circuit, etc.
- Y10T29/4913—Assembling to base an electrical component, e.g., capacitor, etc.
- Y10T29/49146—Assembling to base an electrical component, e.g., capacitor, etc. with encapsulating, e.g., potting, etc.
Definitions
- the present invention relates to mounting and connection devices and techniques for use with microelectronic elements such as semiconductor chips.
- microelectronic devices such as semiconductor chips require numerous connections to other electronic components.
- the microelectronic devices are mounted on substrates or external circuit elements, such as printed circuit boards, having electrical contacts, and the contacts on the chip are electrically connected to the contacts of the external circuit element.
- the external circuit element may have pins or other connectors adapted to accommodate other components, including additional semiconductor chips.
- the external circuit element may have pins or other connectors adapted to connect the contacts or internal circuitry of the external circuit element to a larger assembly, thereby connecting the chip to the larger assembly.
- connections between microelectronic elements and substrates must meet several demanding and often conflicting requirements. They must provide reliable, low-impedance electrical interconnections. They must also withstand stresses caused by thermal effects during manufacturing processes such as soldering. Other thermal effects occur during operation of the device. As the system operates, it evolves heat and the components of the system, including the chip and the substrate expand. When operation ceases, the components cool and contract. When the assembly is heated and cooled during manufacture or in operation, the chip and the substrate expand and contract at different rates, so that portions of the chip and substrate move relative to one another. Also, the chip and the substrate can warp as they are heated and cooled, causing further movement of the chip relative to the substrate. These and other effects cause repeated strain on electrical elements connecting the chip and the substrate.
- the interconnection system should withstand repeated thermal cycling without breakage of the electrical connections.
- the interconnection system should provide a compact assembly, and should be suitable for use with components having closely-spaced contacts. Moreover, the interconnection should be economical.
- flexible leads may be provided between the contacts on a chip or other microelectronic element and the contact pads of a substrate.
- a compliant layer such as an elastomer or a gel may be provided between the chip and the substrate.
- Flexible leads connecting the chip and substrate may extend through the compliant layer.
- the chip is mechanically decoupled from the substrate, so that the chip and substrate can expand and move independently of one another without excessive stress on the electrical connections between the chip contacts and the contact pads of the substrate.
- the assemblies disclosed in these patents and publications meet the other requirements discussed above.
- the chip and the interconnections to the substrate can occupy an area of the substrate about the same size as the chip itself.
- Microelectronic elements such as semiconductor chips generate considerable amounts of heat during use. For example, a complex, high-speed chip only a few centimeters square in area may produce tens of watts of heat. This heat must be dissipated to maintain the chip at a safe operating temperature. Improvements in chip mountings and electrical connections, and in related assembly methods, have made it possible to reduce the distance between chips so as to achieve a more compact assembly. Such assemblies, typically referred to as “multichip modules,” incorporate one or more substrates with chips disposed close to one another on the substrate. The heat dissipation problems discussed above are particularly extreme in such compact multichip modules.
- Thermal insulators have high thermal resistance whereas elements which convey heat effectively by conduction or convection have low thermal resistance.
- the overall thermal resistance of the package is the sum of the individual thermal resistances in series in the heat path between the chip and the ambient environment. The overall thermal resistance in turn provides a ratio between the temperature rise of the chips above ambient temperature and the amount of heat produced in the chips.
- the heat conduction pathway may include an element commonly referred to as a “heat sink.”
- a heat sink There is normally a low thermal resistance connection from the heat sink to the environment.
- the vanes of the heat sink may be bathed in a flow of forced air or liquid.
- Such relative movement arises in part from movement of the components and the substrate bearing the components as the assembly undergoes temperature changes during use.
- the temperature of the chips or other components rises faster than the temperature of the substrate, causing differential thermal expansion, warpage and distortion.
- the coefficients of thermal expansion of the chips and the substrate normally are not matched with the coefficient of thermal expansion of the heat sink, causing further differential thermal expansion and contraction.
- connection between the components and the heat sink should accommodate dimensional tolerances in the components, the substrate and the heat sink itself.
- the chips themselves may be of different thicknesses.
- the chips can be supported at different levels above the face of the substrate by solder balls or other mountings.
- the surfaces of the chips may be tilted from their nominal positions, so that the chip surfaces are out of alignment with the surface of the heat sink.
- the heat sink itself may not be perfectly flat or parallel to the nominal plane of the chip surfaces. Any elements used to connect the heat sink with the chip or the components should be capable of accommodating these tolerances and misalignments. Considerable efforts have been made in the art heretofore towards satisfying these requirements.
- connection components and methods which provide effective mechanical decoupling and high resistance to thermally induced stresses, while also providing low cost and high reliability.
- microelectronic package including improved assemblies and methods for dissipating heat therefrom to minimize thermally induced stresses, while also providing high reliability and low cost.
- One aspect of the present invention provides a method of making a microelectronic assembly including the steps of providing a first microelectronic element, such as a semiconductor chip and a second microelectronic element with confronting spaced-apart surfaces defining a space therebetween and providing one or more masses of a fusible conductive material having a melting temperature below about 150° C. in the space.
- a flowable liquid material typically a liquid
- the flowable material is then cured to form a compliant layer disposed between the confronting surfaces of the first and second microelectronic elements and surrounding each of the fusible conductive masses.
- the one or more conductive masses may be maintained in a substantially solid condition or in a substantially liquid condition when the flowable material is introduced.
- the fusible conductive masses may also be maintained in either a substantially solid condition or in a substantially liquid condition during the curing step.
- the first microelectronic element preferably is a circuit element such as a semiconductor chip.
- the second microelectronic element may be a further circuit element such as a dielectric element having conductors thereon, or else may be a package element such as a casing, heat spreader or heat sink.
- the conductive material is thermally conductive, electrically conductive or both.
- the method desirably includes the step of electrically connecting the first and second elements to one another. For example, the step of providing the masses of fusible conductive material may be performed so that the masses extend between contacts on the confronting surfaces of the first and second microelectronic element, so that the masses electrically interconnect the first and second elements.
- the conductive masses desirably provide a thermal conduction path between the first and second microelectronic elements.
- the one or more fusible conductive masses are contiguous with both elements, and connect the first and second microelectronic elements to one another.
- the fusible conductive masses are contiguous with and are contained by the compliant material, so that the conductive material remains in place when in a liquid state.
- the compliant layer keeps the fusible conductive masses separate and electrically insulated from one another.
- a polymer coating such as a polyparaxylene coating may be provided over the fusible conductive masses.
- the polyparaxylene coating is a conformal coating which preferably fully encompasses the fusible conductive masses and desirably extends to the neighboring portions of the confronting surfaces of the first and second microelectronic elements.
- the coating enhances the electrical isolation of the fusible conductive masses and also protects the masses from contamination, e.g. prevents the fusible conductive material and the compliant layer from diffusing into one another.
- the polyparaxylene coating can also aid in maintaining the masses in place when the masses are in the liquid state.
- the step of providing said first and second elements being performed so that said second microelectronic element confronts a front surface of the first microelectronic element and these elements define a front space therebetween, the conductive masses being provided in said front space.
- a third microelectronic element is provided so that this element confront a rear surface.
- the first and third microelectronic elements define a rear space between said rear surface and said third microelectronic element.
- the first microelectronic element is sandwiched between the second and third microelectronic elements, with front and rear spaces on opposite sides of the first microelectronic element.
- Methods according to this aspect of the invention desirably include the step of disposing one or more additional fusible conductive masses in the rear space and introducing additional flowable material into said rear space and around said conductive masses in said rear space. Most preferably, this additional flowable material is cured to form a rear compliant layer between the third microelectronic element and said first microelectronic element, said rear compliant layer intimately surrounding said conductive masses in said rear space.
- the step of introducing a flowable material into the rear space, and the step of introducing a flowable material into the front space can be preformed by simultaneously using a single flowable material.
- a related aspect of the invention provides a microelectronic package comprising a first microelectronic element such as a semiconductor chip operable in a range of operating temperatures.
- the chip or other microelectronic element has a front face including contacts and a rear surface.
- a compliant layer is disposed between the confronting surfaces of the first microelectronic element and the package element.
- Masses of a fusible, thermally conductive material having a melting temperature within or below the range of operating temperatures of the first microelectronic element are also provided between the package element and the first microelectronic element. Each such mass extends adjacent to the confronting surfaces of the first microelectronic element and the package element for transferring heat therebetween during operation of the microelectronic package.
- the package may also include a second microelectronic element such as a circuit element electrically connected to the first microelectronic element, most preferably a flexible dielectric sheet with terminals thereon, overlying the front face of the first microelectronic element or chip.
- a compliant layer most preferably is provided between the front face and the second microelectronic element.
- masses of a fusible conductive material preferably a material capable of conducting both electrical signals and heat, are dispersed in the second compliant layer so that the fusible conductive masses are spaced apart from one another in lateral directions parallel to the surfaces of the microelectronic elements.
- first and second compliant layers are preferably contiguous with one another.
- the package mechanically isolates the first microelectronic element or chip and effectively decouples it from mechanical stresses and differential thermal expansion, while also providing effective heat transfer from the chip and effective interconnection between the chip and external circuitry.
- the masses of the fusible conductive material used in various aspects of the invention may comprise one or more metals or may comprise a metal alloy and are preferably capable of conducting electrical signals, heat or both.
- the fusible conductive material preferably has a melting temperature below about 125° C., and in more preferred embodiments the fusible conductive material has a melting temperature below about 65° C. Most preferably the fusible conductive material has a melting temperature between about 25° C. and about 65° C. However, lower melting temperatures can be employed if the production process is altered to accommodate the lower melting temperature.
- the conductive masses preferably are liquid at temperatures within the range of temperatures encountered during normal operation of microelectronic elements, and may have a melting temperature below the range of operating temperatures of the microelectronic elements.
- the fusible conductive masses may be in a solid state or a liquid state when the assembly is inactive; however, during operation, the fusible conductive masses may be wholly or partially liquid so that essentially no forces will be transmitted between the microelectronic elements through the conductive masses. Stated another way, the conductive masses in their liquid state have spring constants at or close to zero and do not resist movement of the microelectronic elements relative to one another.
- the conductive material may be a fusible material which melts at temperatures slightly above the range of temperatures encountered during normal operation. In this case, the assembly relieves mechanical stress in the electrical connections or thermal connections, and repairs defects in the connections, when the assembly is exposed to high temperatures during abnormal operating conditions or during processing operations.
- the compliant dielectric layer also allows the microelectronic elements to move relative to one another.
- the dielectric layer desirably is formed from an elastomer, gel, foam or other material having relatively low resistance to deformation.
- Preferred assemblies according to the present invention thus allow electrical signals to pass between microelectronic elements through the fusible conductive masses.
- preferred assemblies according to the present invention also allow heat generated by the microelectronic elements to be effectively dissipated through the package and allow the confronting faces of the microelectronic elements to move relative to one another to compensate for movement and distortion during thermal cycling of the package.
- the compliant connection between the microelectronic elements also helps to compensate for tolerances encountered during manufacturing and can be provided even where each conductor has substantial cross-sectional area.
- low resistance, low impedance conductors can be utilized without impairing the flexible connection.
- the fusible material melts, cracks or other defects in the conductive masses are repaired.
- One or more of the microelectronic elements may include a flexible dielectric sheet having an exterior surface facing away from the other elements and having conductive terminals accessible at the exterior surface.
- the first microelectronic element includes a semiconductor chip
- the second element may include a flexible dielectric sheet overlying a surface of the chip and having terminals facing away from the surface of the chip.
- the front space lies between the flexible sheet and the chip contact bearing face of the chip.
- the method may further include the step of forcing the terminals into substantially coplanar disposition while maintaining the masses of fusible conductive material in an at least partially molten condition. Preferably, this step is performed prior to curing the flowable material, either before or after introduction of the flowable material into the space.
- the conductive terminals are forced into substantially coplanar alignment with one another as the flowable material is introduced therebetween and the conductive masses are allowed to freeze.
- the flowable material is introduced between the confronting surfaces before the conductive terminals are forced into substantially coplanar alignment.
- the flexible sheet and the chip or other element have contacts on their opposing surfaces. Fusible conductive masses are provided between the opposing contacts to electrically interconnect the chip and the dielectric sheet. Additional fusible conductive masses, aside from those used for electrical interconnection, may be provided between the confronting faces of the chip and the dielectric sheet to provide additional conduct heat therebetween.
- the dielectric sheet includes conductive terminals accessible at the exterior surface and flexible leads are used to connect the conductive terminals of the dielectric sheet with the contacts of the semiconductor chip. Fusible conductive masses are provided between the confronting faces of the chip and the dielectric sheet for conducting heat therebetween during operation.
- one or more of the microelectronic elements may include a plurality of semiconductor chips.
- the first microelectronic element may include a unitary wafer incorporating a plurality of semiconductor chips
- the second microelectronic element may include a flexible dielectric sheet as described above.
- Each chip is preferably aligned with a portion of the sheet and the contacts on each chip may be connected by the fusible conductive masses to the terminals in the aligned portion of the sheet.
- the method according to this aspect of the invention may include the further step of severing individual portions of the sheet and wafer to form individual units, each including one or more chips and the portion of the sheet aligned therewith.
- the step of providing the microelectronic elements and the fusible conductive masses may include the step of providing the masses attached to contacts on one of the microelectronic elements and then juxtaposing the elements with one another and at least partially melting the masses to thereby bond the masses to the contacts on the other element.
- the masses may be provided on the wafer, and the wafer may be juxtaposed with the flexible dielectric sheet.
- the second microelectronic element has electrically conductive traces thereon, and a plurality of chips are electrically connected to the second element, as by connection through conductive masses as discussed above, so that the chips are interconnected to one another to form a multichip module.
- Further methods of making a microelectronic assemblies according to the invention include the steps of providing a metallic plate, juxtaposing the plate with a surface of a microelectronic element and providing one or more masses of a fusible conductive material so that the masses extend in a space between the plate and the microelectronic element, and preferably extend all the way from the plate to the microelectronic element.
- the plate is provided with the more masses of a fusible conductive material disposed at predetermined locations on a surface thereof before juxtaposing the plate with the microelectronic element.
- Methods according to this aspect of the invention desirably include the step of injecting a flowable material between the metallic plate and the microelectronic element and curing the flowable material to form a compliant dielectric layer which intimately surrounds the fusible conductive masses.
- the predictable, isotropic thermal expansion properties of the metallic plate help to provide precise alignment of the fusible conductive masses with the contacts on the microelectronic element.
- the metallic plate is then subdivided to form separate portions connected to separate ones of the fusible conductive masses.
- the microelectronic element may include an array of semiconductor chips or a semiconductor wafer.
- the metallic plate may be subdivided by etching the plate after the flowable material is cured.
- the metallic plate with the fusible conductive masses may be provided by forming a layer on a first side of the metallic plate whereby the layer has apertures therein and includes a material, such as a polymer, which is non-wettable by the conductive masses.
- the first side of the plate is then exposed to the fusible conductive masses while the conductive masses are in a molten condition so that drops of the fusible conductive masses adhere to the metallic plate at the apertures therein.
- the first side of the plate is preferably exposed to the conductive masses by dipping the metallic plate into a bath of the fusible conductive material.
- a second side of the metallic plate opposite from the first side thereof may be covered by a protective coating during the exposing step to prevent the second side of the metallic plate from coming into contact with the fusible conductive material.
- Barrier layers such as a layers of polysilicon, may be provided on surfaces of the microelectronic elements which are in contact with the fusible masses, such as on contacts or on surfaces of package elements.
- the barrier layer prevents the material in the fusible conductive masses from diffusing into the microelectronic element, the opposing contacts and/or the package element.
- the barrier metal layer also prevents contamination of the fusible material by the microelectronic element and/or the package element.
- a structure according to this aspect of the present invention includes a layer of a matrix material having top and bottom surfaces extending in lateral directions.
- One or more masses of a fusible conductive material are dispersed in the layer so that the individual conductive masses are spaced apart from one another in the lateral directions and are separated from one another by the matrix material.
- the fusible conductive masses preferably include one or more metals and preferably have a melting temperature below about 125° C. and more preferably below about 65° C. In certain embodiments, at least some of the fusible conductive masses extend over a major portion of the distance between the top and bottom surfaces of the layer.
- the fusible conductive masses extend from the top surface to the bottom surface of the layer to provide a continuous conductive path from the top surface to the bottom surface of the layer.
- the matrix material is selected from the group consisting of (a) compliant materials having a degradation temperature higher than the melting temperature of the fusible conductive masses and (b)flowable, curable precursor materials.
- This structure may be provided as a prefabricated structure, without microelectronic elements. The prefabricated structure may be used with one or more microelectronic elements to provide a compliant, thermally conductive connection, and may also be used to provide a compliant electrically conductive connection. The structure may also include one or more removable release layers overlying at least one of the surfaces of the layer of matrix material.
- the release layer protects the structure from contamination during storage and may be removed from the structure shortly before final assembly of the structure with a microelectronic package.
- the structure may also include an adhesive overlying at least one of the top and/or bottom surfaces of the matrix layer so that the structure may be easily assembled to the surface(s) of one or more microelectronic elements.
- the matrix material itself may be capable of bonding to a surface of a microelectronic element.
- Assembly methods using such components For example, a layer as aforesaid may be assembled to one or more semiconductor chips, whereby each semiconductor chip has a surface in engagement with a surface of the layer.
- the layer may be applied to a surface of a wafer or to an assemblage of individual chips, and the resulting assembly may be severed to provide individual units including one or more chips and a portion of the layer.
- FIG. 1 is a fragmentary, diagrammatic sectional view depicting a stage in a manufacturing process according to one embodiment of the invention.
- FIG. 2 is a diagrammatic perspective view depicting a wafer utilized in the process of FIG. 1.
- FIG. 3 is a diagrammatic perspective view depicting a subassembly made by the process of FIG. 1.
- FIG. 4 is a diagrammatic, fragmentary sectional view depicting an assembly made using the subassembly of FIG. 2.
- FIG. 5 is a diagrammatic, sectional view similar to FIG. 4, but depicting a portion of an assembly in accordance with a further embodiment of the invention.
- FIG. 6 is a fragmentary sectional view depicting a component in accordance with yet another embodiment of the invention.
- FIG. 7 is a diagrammatic elevational view of an assembly incorporating the subassembly of FIG. 6.
- FIG. 8 is a diagrammatic perspective view depicting a component in accordance with a further embodiment of the invention.
- FIG. 9 is a fragmentary view on an enlarged scale depicting portions of an assembly in accordance with a further embodiment of the invention.
- FIG. 10 is a diagrammatic sectional view of an assembly in accordance with a further embodiment of the invention.
- FIGS. 11 through 14 are fragmentary diagrammatic sectional views of an assembly during successive stages in a fabrication process in accordance with another embodiment of the invention.
- FIG. 15 is a view similar to FIGS. 11 - 14 but depicting an assembly in accordance with yet another embodiment of the invention.
- FIGS. 16 is a fragmentary diagrammatic sectional view depicting elements according to further embodiments of the invention.
- FIG. 17 is a fragmentary diagrammatic-sectional view depicting elements according to yet another embodiment of the invention.
- FIG. 18 is a further fragmentary diagrammatic sectional view depicting elements during a process according to another embodiment of the invention.
- FIG. 19 is a fragmentary diagrammatic sectional view depicting elements according to still another embodiment of the invention.
- FIG. 20 is a diagrammatic sectional view depicting an assembly in accordance with yet another embodiment of the invention.
- FIG. 21 is a diagrammatic, partially cutaway, perspective view depicting an assembly in accordance with yet another embodiment of the invention.
- FIG. 22 is a diagrammatic sectional view depicting an assembly in accordance with yet another embodiment of the invention.
- FIG. 23 is a fragmentary diagrammatic sectional view depicting an assembly in accordance with a further embodiment of the invention.
- FIG. 24 is a diagrammatic sectional view of an assembly in accordance with another embodiment of the invention.
- FIG. 25 is a diagrammatic sectional view of an assembly in accordance with still another embodiment of the present invention.
- An assembly in accordance with one embodiment of the invention includes as a first element a unitary semiconductor wafer 22 incorporating a large number of semiconductor chips 28 disposed side by side.
- the wafer has numerous contacts 24 disposed on its top or front surface 26 .
- a rear surface 27 is devoid of contacts.
- Each contact includes a small spot of a metal such as aluminum, gold, copper, zinc or tin.
- the wafer is formed in the normal fashion, with numerous semiconductor devices within each chip 28 connected to one another and to contacts 24 by internal circuitry (not shown) formed within the wafer.
- the wafer also has narrow strip-like regions 30 , commonly referred to as “saw lanes” or “scribe streets” extending between adjacent chips 28 .
- the second element of the assembly includes a flexible, but substantially inextensible dielectric sheet 10 having a first surface 12 and a second surface 14 .
- sheet 10 may be a sheet of polyimide about 25 microns or less thick.
- Vias are formed through sheet 10 and filled with a metallic material to form solid via liners or terminal assemblies 15 extending through the sheet at predetermined locations.
- Each via liner defines a contact 16 at the first surface 12 of sheet 10 and a terminal 17 at the second surface of the sheet.
- the terminal assemblies 15 may be formed from any suitable metal which can be conveniently deposited in the vias as, for example, copper and copper alloys.
- Each contact 16 is provided with a layer 18 of a barrier material, such as a polycrystalline silicon, on the exposed face of the contact.
- the barrier material is selected to resist dissolution in the low-melting fusible conductive metal discussed below, and to prevent difflusion of the underlying material of the contact in the fusible metal.
- the composition of the barrier layer will depend in part upon the composition of the fusible metal. Metals such as nickel, tungsten, titanium and their alloys normally can be used as barrier layers with typical fusible metals such as ultra-low melting solders of the types discussed below.
- the barrier layer 18 may also include a polycrystalline silicon or polysilicon. Barrier layer 18 need only be thick enough to inhibit dissolution of the underlying metal in the contact 16 . A layer of barrier material about 1 micron thick typically is sufficient.
- the barrier layer material desirably is wettable by the fusible conductive metal when the fusible conductive metal is in its liquid state.
- the barrier layer may also include a plurality of layers of different compositions.
- Terminals 17 have bonding material layers or masses 20 thereon. Essentially any conventional bonding material can be employed, including conventional solders, conductive polymers, and eutectic bonding materials, also referred to as diffusion-bonding alloys. The bonding material is selected to provide satisfactory connection to the contact pads engaged with the terminals in service, as further discussed below.
- masses 42 of a fusible conductive material such as an ultra-low melting point solder are deposited on the contacts 24 of wafer 22 .
- This step of the process may be performed by conventional equipment and techniques commonly used to deposit solder masses on microelectronic elements.
- the masses may be applied individually or, by screening the fusible conductive material onto the surface of the wafer using a mask or screen with perforations corresponding to the contacts, and then removing the mask.
- the mask may be formed separately from the wafer or may be formed in place on the top surface of the wafer by photolithographic techniques.
- the mask may be removed from the wafer by mechanically separating the mask and wafer or by dissolving the mask after deposition of the fusible metal. Suitable fluxes may be employed during deposition of the fusible metal on the wafer. The flux may be removed after deposition of the fusible metal. After the fusible metal has been deposited on the contacts of the wafer and the mask has been removed, the fusible metal may be briefly re-melted so as to reflow the fusible metal and bring it into even more intimate contact with the contacts of the wafer.
- the melting temperature of the fusible conductive material desirably is within or below the normal operating temperature of the semiconductor elements in the wafer, or only slightly above the normal operating temperature range.
- the normal, expected range of operating temperatures of the semiconductor elements will depend upon the configuration and composition of the element, and upon the operating environment encountered in service. Typical silicon-based semiconductor elements are designed to operate at about 40°C. to about 85°C.
- the term “melting temperature” as used in this disclosure should be understood as referring to the solidus temperature, i.e., the temperature at which the metal begins to melt (when heated slowly) or completes freezing (when cooled slowly).
- the melting temperature of the fusible conductive material is above normal room temperature (20°C.) so that the fusible conductive material can be handled conveniently in solid form during the steps discussed below.
- the fusible conductive material desirably has a melting temperature of less than about 150°C., preferably less than about 125°C. and more preferably less than about 100°C. Melting temperatures below about 85°C. are more preferred, and melting temperatures below about 65°C. are even more preferred. The range of melting temperatures between about 25°C. and 65°C. is particularly preferred, and melting temperatures between about 35°C. and about 55°C. are especially preferred. However, lower melting temperatures can be employed if the production process is altered to accommodate the lower melting temperature.
- Suitable low-melting point solders are the following: COMPOSITION 1 COMPOSITION 2 ELEMENT WEIGHT % WEIGHT % Sn 18.5 10.5 Bi 45 40 Pb 24 21.5 In 10 20 Cd 9.5 8 Melting 55° C. 50° C. Temperature
- Solders having compositions intermediate between the two low-melting point solders illustrated in Table 1 can be used.
- Other suitable low-melting solders include the solder sold under the trademark Indalloy by the Indium Corporation of America, in Clinton, N.Y.
- Indalloy Number 8 has a melting point of about 93°C.
- Indalloy Number 117 has a melting point of about 47°C.
- Still other low-melting solders include other combinations of metals selected from the group consisting of cadmium, bismuth, tin, lead and indium in various proportions, with or without other metals. Additional fusible metals include mercury and mercury containing alloys.
- the dielectric sheet or second element 10 is assembled to the wafer or first element 22 so that the first surface 12 of the sheet faces toward the front surface 26 of the wafer and these confronting surfaces define a space 46 between them.
- the contacts 16 of the dielectric sheet or second element are aligned with the contacts 24 of the first element and aligned with masses 42 of fusible conductive material disposed on the first element contacts.
- the alignment between the contacts 16 of the second element and the fusible conductive masses 42 need not be perfect. The alignment need only be close enough that each contact 16 on the second element touches the correct fusible conductive mass 42 during the melting step discussed below, and so that each contact 16 on the sheet or second element does not touch any other fusible conductive mass 42 .
- the sheet While the assembly is in this taut condition at elevated temperature, the sheet is then bonded to a frame formed from a material such as molybdenum having a coefficient of thermal expansion close to that of the sheet, and the ring is removed.
- the assembly of the frame and the sheet can then be cooled to room temperature and the sheet will remain taut.
- the taut sheet can be aligned with wafer using a manually adjustable device such as a micrometer-actuated microscope stage by an operator while the operator observes the sheet and wafer under magnification.
- the alignment step also can be performed robotically, using generally conventional machine-vision systems.
- both the dielectric sheet and the wafer are provided with fiducial marks to be used as a reference in alignment.
- the sheet typically is transparent and hence the fiducial marks on the wafer can be observed through the sheet by a human operator or by a machine vision system.
- the sheet and the wafer are aligned with one another, the sheet is pressed inwardly, toward the wafer so that the exposed surfaces of the contacts on the first or inwardly facing surface 12 of sheet 10 engage the fusible conductive masses 42 .
- This can be accomplished by placing the elements between a pair of plates 48 and 50 so that a first plate engages wafer 22 on its bottom or outwardly facing surface whereas a second plate engages sheet 14 along its top or outwardly facing surface 14 , and urging plates 50 and 48 towards one another.
- plate 50 may be provided with pockets or recesses corresponding to the terminals. The sheet may be held in engagement with plate 50 by application of vacuum through ports 52 in the plate.
- plate 50 can be provided with a resilient covering such as a foam on the surface of the plate which engages the sheet surface.
- a rigid stiffening plate (not shown) may be provided between plate 50 and the sheet surface. A gas or other fluid may be introduced between plate 50 and the stiffening plate so that the fluid pressure urges the stiffening plate and the sheet inwardly, towards the wafer until the stiffening plate and sheet reach a stop (not shown).
- the conductive masses While the contacts are held in engagement with the fusible conductive masses, the conductive masses are brought to a temperature above their melting temperature, so that the conductive material at least partially liquefies and flows into intimate engagement with the exposed surfaces of the contacts 16 on the sheet. This may be accomplished by heating the assemblage after the second element or sheet 10 has been engaged with the wafer and conductive masses. Alternatively, the wafer and the conductive masses may be at a temperature above the melting temperature of the fusible conductive material prior to engagement of the sheet. The sheet and hence the contacts 16 can also be preheated to a temperature above the melting temperature of the fusible conductive masses before engagement with masses 42 .
- the molten conductive material wets the barrier metal 18 on the surfaces of contacts 16 .
- a flux may be employed in this step as well. Any flux used in the process may be removed by flushing space 46 with a suitable solvent and removing the solvent. While the masses are in at least a partially molten condition, plate 50 holds the sheet and hence terminals in a substantially planar condition, with the exposed surfaces of the terminals on the second or outwardly facing surface 14 of the sheet in substantially coplanar alignment with one another. The plates also maintain the alignment of the contacts 16 and masses 42 in horizontal directions, parallel to the opposed surfaces 26 and 12 of the first and second elements.
- the conductive masses are cooled to below their melting temperature, as by cooling the entire assemblage, including plates 50 and 48 . If the fusible masses 42 were only partially melted, as where the masses were originally at below-melting temperatures and the contact 16 were at temperatures above the melting temperature, the partially melted portion of the masses can be cooled by heat transfer to the remaining portions of the mass.
- a polymer such as a polyparaxylene coating 43 may be provided over the fusible conductive masses 42 .
- the polyparaxylene coating 43 is a conformal coating which fully encompasses the fusible conductive masses 42 and the adjacent regions of the contacts 16 and 24 .
- the coating extends between the confronting surfaces of the dielectric sheet 10 and the wafer 22 , and may cover portions of these surfaces as well.
- the coating 43 helps to retain the fusible masses 42 in place when they are in a molten condition and helps preserve the electrical isolation of the fusible conductive masses 42 from one another.
- the coating also helps to prevent cross-contamination; the coating prevents the fusible conductive material and the material of the compliant layer from diffusing into one another.
- the polymeric coating may be provided by a vapor-phase coating process of known type.
- a flowable, preferably liquid material is introduced into space 46 between confronting surfaces 12 and 26 so that the flowable material fills the space and intimately surrounds masses 42 and the adjacent surfaces of contacts 16 and 24 .
- the flowable material also intimately contacts the inwardly facing surfaces 12 and 26 of the sheet and wafer.
- the contact 16 and sheet 10 are maintained in substantially planar disposition, and the contacts are maintained in alignment with masses 42 . Alignment and planarity can be maintained by adhesion between the frozen masses 42 and contacts 16 , without external fixturing at this stage.
- plates 48 and 50 of the fixture used during the melting and freezing steps discussed above remain in place.
- the assemblage of the wafer can be removed from this fixture after freezing and placed into another, similar fixture prior to injection of the flowable material.
- the fixtures will help to maintain the coplanarity and alignment during injection of the flowable material.
- the flowable material may be introduced while the fusible conductive masses are in their liquid state.
- the flowable material desirably has relatively low viscosity and is essentially immiscible with the molten fusible conductive material.
- many organic materials, such as silicone gel components are immiscible with liquid metals. The surface tension of the liquid fusible material on the opposing contacts tends to maintain the molten masses in place.
- the flowable material may wet the opposing surfaces of the sheet and wafer, so that flow of the material into space 46 is aided by capillary action.
- the flowable material is cured to form a compliant resilient layer 54 occupying space 46 and intimately surrounding the fusible conductive masses 42 and contacts.
- the compliant layer after curing, should have some resistance to deformation.
- the compliant layer may be a solid or a gel.
- the compliant layer may incorporate voids, and indeed may take the form of a solid or gel foam.
- the compliant layer should form substantially continuous surfaces surrounding the conductive material masses 42 .
- the compliant material has an elastic modulus less than about 100,000 pounds per square inch, and still lower values of elastic modulus are more preferred.
- the compliant layer desirably has relatively low resistance to shear between opposed surfaces 12 and 26 .
- the compliant layer is between about 50 and 250 microns thick.
- the compliant layer desirably has a low spring constant per unit area when stressed in shear between opposing surfaces 12 and 26 .
- the compliant layer desirably also has a relatively low spring constant with respect to displacement of surfaces 12 and 26 towards and away from one another.
- the compliant layer 54 desirably remains soft and cohesive over a range of temperatures encompassing at least the range from the melting temperature of the fusible conductor material 42 to above the normal operating temperatures of the chips 28 constituting the wafer.
- the compliant layer desirably retains these properties from about 20°C. or below to about 45° C. or higher.
- the compliant layer retains properties in the aforesaid ranges from about 0°C. or below to about 60°C. or above. Most preferably, the compliant layer retains the desired properties from about ⁇ 65°C. or below to about 150°C. or above.
- the flowable material may be introduced around the fusible conductive masses 42 when the masses are in a liquid state. The fusible masses 42 may then be frozen before the flowable material cures or after the flowable material cures.
- the flowable material used to form layer 54 should be capable of flowing, prior to cure, at temperatures below the melting temperature of the fusible conductive material in masses 42 .
- the flowable material may be injected under pressure.
- space 46 may be evacuated prior to injection of the flowable material.
- Techniques for evacuation of a space between a flexible sheet and wafer and for injection of flowable, curable materials into such a space are further disclosed in the aforementioned International Patent Publication 96/02068 and United States Provisional Patent Application 60/001,718.
- Suitable flowable materials for forming the compliant layer include polymer compositions which are initially in the form of liquids but which cure by chemical reaction of their ingredients to form a solid or gel.
- compositions that can be used are silicones, epoxies and urethanes.
- Particularly suitable compositions include silicone gels of the type sold under the designation Sylgard 577 Curable Silicone Gel by the Dow-Corning Corporation of Midland, Mich.
- Other suitable silicon gels are available from the Shin-etsu Corporation and from the General Electric Corporation of Schenectady, N.Y.
- the reaction-curable material may be provided as two mutually reactive components which are mixed immediately prior to introduction of the material into space 46 and which react spontaneously with one another at ambient temperature.
- Other reactive polymer compositions can be activated by application of ultraviolet light.
- the curing step can also be initiated or accelerated by heating the reactive polymer composition.
- Some or all of the curing step may entail temperatures above the melting temperature of the fusible material in masses 42 . In this case, it is desirable to maintain alignment of the elements, and maintain planarity of the contacts 16 on the sheet by holding the assemblage in a fixture during at least the elevated temperature portions of the curing step.
- wafer 22 , sheet 10 and the compliant layer 54 are severed by cutting along saw lanes 30 , using a saw of the type commonly used for dicing wafers.
- Each unit includes one chip 28 as well as a portion of compliant layer 54 overlying the chip and a portion of sheet 10 overlying the chip.
- Each unit has terminals 17 with exposed bonding material 20 on the side of sheet 10 facing away from the chip, and each unit has its contact 16 connected to the corresponding contacts of the chip by fusible conductive masses 42 .
- These units can be handled and placed like other surface mountable electronic devices. As seen in FIG.
- unit 58 can be placed on a substrate 60 .
- Substrate 60 has internal electrical circuitry 62 and contact pads 64 connected to such circuitry and disposed on a surface of the substrate.
- the outwardly facing second surface 14 of flexible layer or second element 10 is juxtaposed with the surface of the substrate, so that the exposed surfaces of terminal 17 and bonding material 20 are engaged with contact pads 64 .
- the assembled parts are brought to an elevated temperature so as to activate the bonding material 20 and bond terminals 17 to contact pads 64 on the substrate.
- the fusible conductive masses 42 melt.
- the fusible conductive material of each mass is contained by the surrounding compliant layer, as well as by the first element or chip 28 and the second element or flexible sheet 10 and the contacts on these elements.
- the fusible conductive masses 42 may also be contained by the polymer coating around the masses. Therefore, the fusible conductive material remains in position and maintains electrical continuity between contact 16 and contact 24 on the chip. While unit 58 is in this condition, contacts 16 and terminals 17 can be displaced readily relative to chip 28 . For example, if the contact pads on substrate 60 are out of plane, or if substrate 60 is tilted out of parallelism with chip 28 , all terminals 17 can still be brought into engagement with contact pads 64 without applying destructive forces to the unit. After bonding, the assembly can be cooled, whereupon the flowable material in masses 42 will freeze.
- substrate 60 incorporates additional electronic components, such as additional semiconductor chips and other components electrically interconnected with chip 28 through the conductors 62 and contact pads 64 of the substrate and through terminals 17 , contacts 16 and fusible conductive masses 42 .
- substrate 60 may include further connectors such as contact pads 66 or other devices such as sockets, pins for engagement in sockets, wires or other conventional interconnection devices for connecting circuitry 62 of substrate 60 with a still larger circuit.
- the assembly is quite compact; each unit 58 occupies an area on the surface of substrate 60 about the same size as the area of chip 42 itself.
- the assembly may be incorporated in an electronic device such as a computer, a communications device, or an electronic device associated with a non-electronic machine such as an automobile or an industrial machine.
- electrical signals pass through the substrate and chip via the contacts and fusible conductive masses. Electrical power is converted to heat in the device, principally in semiconductor chip 28 and in other electronic elements of the device. The heat raises the temperature of the chip and the surrounding elements. As the temperature of the device rises, the fusible conductive masses 42 melt and are contained by the surrounding elements of the structure, including compliant layer 54 , chip or first element 28 and the flexible layer or second element 10 and the contacts 16 and 24 on those elements.
- each contact 24 on the chip typically moves with respect to the corresponding contact 16 of the flexible sheet 10 or second element.
- the chip 28 tends to expand, thereby moving contacts 24 relative to the contact pads 64 of the substrate.
- the contacts on the chip will move relative to the contact pads of the substrate as the entire assembly is heated. Even where the coefficients of thermal expansion are the same, differential movement will occur if the temperature of the chip rises or falls at a different rate than the temperature of the substrate. Also, the chip, the substrate or both can warp as they undergo thermal expansion and contraction.
- the device cools and the fusible conductive masses 42 may freeze again.
- the cycle of melting and freezing may be repeated numerous times during the service life of the device. Defects which may occur in masses 42 are automatically repaired when the masses melt and freeze.
- the conductive material and the masses 42 may remain liquid indefinitely.
- the metal in barrier layer 18 of contact 16 is selected to prevent dissolution of the base metal of the contact into the molten conductive material.
- the contacts 24 of the chip are formed from metals which will not dissolve in the fusible conductive material. This assures that the composition of the conductive material will remain essentially unchanged and hence its melting temperature will not vary during continued use of the device.
- Compliant layer 54 protects the fusible conductive material from contamination and helps to assure reliability of the device.
- Additional packaging may be provided around the chip and substrate.
- the chip and substrate may be encapsulated in a flexible encapsulant.
- the encapsulant may also penetrate between layer 10 and substrate 60 .
- Other conventional packaging elements such as metallic shields or “cans”, heat spreaders and the like may be included in the assembly.
- further fusible conductive masses may be provided between the chip or other first microelectronic element and the packaging element to conduct heat for dissipating heat from the assembly.
- the finished unit 58 may be tested by engaging it with a test substrate so as to engage the exposed surface of each terminal 17 with a contact on the test substrate and then operating chip 28 by applying signals through the terminals. Prior to or during such engagement, unit 58 is heated to a temperature high enough to melt the fusible conductive masses 42 , but not high enough to activate the bonding material 20 on the contacts. This allows the compliant layer 54 and masses 42 to deform and hence allows the terminals 17 on the exposed surface of the unit to engage the contacts of the test substrate even where the test substrate and/or terminals 17 are not precisely coplanar.
- An assembly according to a further embodiment of the invention includes a substantially rigid first element such as a chip 128 with contacts 124 on a front surface 126 , and also includes a substantially rigid second element such as a substrate 160 with contacts 164 on an interior surface.
- the contact-bearing surface 126 of the chip overlies the contact-bearing surface of the substrate.
- masses of a fusible conductive material 142 are disposed between contacts 124 and contacts 164 .
- Masses 142 are surrounded by a compliant layer 154 substantially filling the space between the confronting surfaces of the first and second elements and intimately surrounding masses 142 .
- the contacts are provided with barrier layers to avoid dissolution of the contact metals in the fusible conductive material.
- Structures according to this embodiment may be fabricated by assembling the first and second elements with the fusible conductive material masses, momentarily melting the masses by heating the assembly and then freezing the masses. These steps may be performed using techniques similar to those used in the so-called controlled collapse chip connection technique, commonly referred to as “C4” bonding. C4 bonding is described in detail in Multi-Chip Module Technologies and Alternatives-the Basics, Doane and Franzon, eds; 1993, pp. 450-476 and 434-446, the disclosure of which is hereby incorporated by reference herein.
- compliant layer 154 is formed by injecting a flowable material as an encapsulant into the space between the confronting surfaces of the chip and substrate and curing the flowable to form a solid, gel or form as discussed above. Assemblies according to this aspect of the present invention provide benefits similar to those discussed above. Once again, at operating temperature, the chip is mechanically connected to the substrate only through the compliant layer 154 .
- Masses 142 are molten and hence provide essentially no resistance to relative movement between the chip and substrate contacts or between the chip 128 and the substrate 160 as a whole.
- solder joints remain solid at operating temperature and are subjected to fatigue stresses during thermal cycling.
- connection component 200 including a compliant layer 254 with a first surface 253 and a second surface 255 . Holes or cavities 243 extend through the compliant layer. A mass 242 of a fusible conductive material is disposed within each hole or cavity 243 .
- a connection component according to this aspect of the invention can be fabricated by procedures similar to those discussed above. However, in this instance the first element 210 and second element 222 are both held in a taut condition and aligned with one another with fusible conductive masses 242 disposed therebetween.
- connection components can be used for interconnecting other microelectronic elements such as a chip and a substrate.
- the connection component can be placed between confronting surfaces of an element such as a chip 280 and another element such as a substrate 282 (FIG. 7) so that first terminals 260 face the contacts of chip 280 whereas second terminals 261 face the contacts of substrate 282 .
- the assemblage is heated to a temperature sufficient to activate the solder or bonding materials 263 , 264 on the terminals, thereby fusing the terminals to the contacts of the chip and substrate.
- the fusible conductive material 242 melts, but is retained in position by compliant layer 254 .
- the compliant layer can bend and compress locally as required during this bonding process, to assure good engagement between terminals 260 and 261 and the contacts of the chip and substrate.
- a further encapsulant may be introduced between sheet 222 and chip 280 , and between sheet 222 and the substrate, to fill voids in these regions.
- the fusible conductive masses 242 melt and allow contacts 258 , fixed to the chip, to move relative to contacts 262 on the substrate.
- a simpler connection component includes a layer of a matrix material 354 having oppositely directed top and bottom surfaces 353 , 355 extending in lateral directions.
- the matrix material may include compliant materials having a degradation temperature higher than the melting temperature of the fusible conductive masses or curable precursor materials.
- the compliant material may be of the same types as discussed above.
- a curable precursor matrix material may be formed from the flowable materials discussed above, but preferably has somewhat greater cohesion.
- a curable precursor matrix material can be formed by partially curing a flowable liquid material to provide a material which is still deformable but which has some cohesion and which will remain in place.
- fillers such as silica may be added to a flowable material to make it highly thixotropic.
- the matrix layer defines holes or cavities 343 extending between these surfaces.
- Masses 342 of a flowable conductive material are disposed within cavities 343 .
- the individual fusible conductive masses are dispersed in the layer of matrix material so that the masses are spaced from one another in the lateral directions and separated from one another by the matrix material.
- the fusible conductive masses preferably are formed from fusible materials of the types discussed above.
- Each mass 342 has an exposed portion 352 at the first surface of matrix layer 354 and a similar exposed portion 354 at the second surface.
- a first removable release liner 357 A overlies the top surface 353 of the layer 354 and a second release liner 357 B overlies the bottom surface 355 of the layer 354 .
- a thin layer of an adhesive 359 optionally may be provided over the top surface 353 or the bottom surface 355 , as by coating these surfaces before the release liners 357 A and 357 B are provided and preferably before masses 342 are provided.
- the release liners isolate the layer 354 and the masses 342 from contaminants during storage.
- the compliant layer 354 can be injection molded to form cavities 343 and then filled with the flowable conductive material.
- the interior surfaces of holes 343 may be treated to improve wettability of the compliant material by the conductive material, as by electroless plating of the interior surfaces of the holes.
- the masses 342 can be placed into a mold and a liquid material may be introduced into the mold and solidified around the masses in the manner discussed above.
- Components according to FIG. 8 may be provided, handled and stored separately from the microelectronic elements. These components can be used to interconnect opposed microelectronic elements similar to those shown and described above. In such an assembly process, the component is assembled with one microelectronic element, so that the top or bottom surface of the matrix layer is engaged with the microelectronic element. Where the conductive masses are to provide circuit interconnection, this assembly procedure should be performed so that the conductive masses are engaged with contacts on the microelectronic element. The opposite microelectronic element is engaged with the other surface of the matrix layer in similar fashion. Preferably, the matrix layer is bonded to the surfaces of the microelectronic elements.
- compliant layer 354 itself may be arranged to adhere to the surfaces of the mating elements.
- matrix layer 354 may be formed as a partially cured or “B-stage” material. When the component is engaged between mating elements and heated to melt masses 342 , the partially cured material fully cures and bonds with the surfaces of the mating elements. Once the component is assembled with the opposed microelectronic elements, the contacts on the opposed elements bear on the fusible conductive masses 342 and help to contain the masses within holes 343 . The resulting assembly may have a configuration similar to the assembly of FIG.
- the fusible conductive material bears directly on the contacts of the elements such as a chip and a substrate
- the surfaces of compliant layer 354 bear directly on these elements.
- FIG. 8 Separately-formed components as shown in FIG. 8 are particularly useful in providing thermally conductive connections between elements. In this use, the components can be applied to surfaces of microelectronic elements without regard for locations of electrical contacts. In one process, a large component as shown in FIG. 8 is applied to the rear surface 27 of a wafer (FIG. 2) before the wafer is severed to separate the individual chips from the wafer.
- each severed chip includes a matrix layer conductive masses on its rear surface, which can be used to mount the rear surface on a circuit board or to connect a package element such as a heat spreader or heat sink to the chip.
- a process can be performed in conjunction with processes as discussed above for providing similar masses on the front or contact-bearing surface.
- a component as depicted in FIG. 8 may include terminal assemblies as depicted in FIGS. 6 and 7 on one or both sides of the compliant layer without the flexible sheets 210 , 222 , or with such a flexible sheet on only one side.
- Alpha radiation is known to damage the electronic components incorporated in semiconductor chips and to cause momentary errors in operation of such components.
- Fusible conductive materials which contain heavy metals typically contain small amounts of radioactive isotopes which emit alpha particles.
- Several measures may be taken to control the effects of alpha radiation on the underlying chip.
- One such approach is to limit the amount of alpha particle radiation emitted by controlling the radioactive isotope content of the fusible conductive material.
- the physical configuration of the contacts and fusible conductive masses may be selected to limit the effects of alpha radiation. Ordinarily, the contacts themselves provide effective shielding against alpha radiation.
- Alpha particles normally cannot pass directly through a metallic contact into the underlying electronic components of the chip.
- the alpha radiation emitted by fusible conductive mass 442 a normally cannot pass directly through contact 424 a .
- Any deleterious effects of alpha radiation on the chip are caused by alpha particles passing around the edges of the contact along paths such as path 443 .
- Simply increasing the thickness of contact 424 a limits the effect of such alpha radiation.
- the contact may have a larger diameter than the fusible conductive mass.
- contact 424 b has a diameter D c substantially larger than the diameter D m of mass 442 b at the juncture of the mass and contact. This assures that any alpha radiation passing around the periphery of the contact will pass along a path 443 b at a relatively low angle to the chip surface.
- the contact is provided with a ring of a material which is not wettable by the fusible conductive material.
- the polyparaxylene coating described above may maintain the fusible conductive mass in place when the mass is in its liquid state.
- the contact or the barrier metal at the surface of the contact adjacent the fusible conductive mass may be non-wettable by the fusible material.
- a small spot adjacent to center of the contact may be plated with a metal which is wettable by the fusible material.
- the mass 442 b is tapered inwardly towards its central axis in the vertical direction upwardly, away from the contact 424 b . This further assures a long path length from the mass surface to the chip surface.
- Such tapered masses can be produced by processes such as that discussed above with reference to FIG. 8.
- the masses can be tapered by techniques commonly used in the C4 bonding art, as by momentarily moving chip 428 away from the mating element 410 while the fusible conductive material is in a molten state.
- an assembly in accordance with a further embodiment of the invention includes a chip or first element 522 and a second element 510 including a flexible multilayer sheet.
- Sheet 510 has contacts 516 on a first side facing inwardly, toward the chip or first element, and has terminals 517 on the opposite, outwardly-facing side.
- contacts 516 are disposed in a pattern corresponding to the pattern of contacts 524 on the chip.
- Terminals 517 are not integral with contacts 516 . Instead, the terminals are distributed on the outwardly-facing side of sheet 510 in an array different from the pattern of contacts 516 . In the depicted embodiment, terminals 517 occupy a larger area of the sheet than contacts 516 .
- Terminals 517 are connected to contacts 516 by leads 519 extending within sheet 510 .
- Sheet 510 may be a multilayer structure, with the leads disposed between layers.
- the assembly further includes additional electrical elements 580 mounted to sheet 510 and electrically connected to leads 519 , so that the additional elements are connected between some of contacts 516 and terminals 517 .
- the additional elements may include any circuit element, but most typically include capacitors.
- the capacitors typically are connected to the terminals and contacts which form the power and ground connections to the chip.
- the electrical contacts 524 of the first element or chip 522 are connected to the contacts 516 by fusible, electrically-conductive masses 542 .
- the assembly further includes a package element adapted to physically support and protect the chip and additional electrical elements.
- the package element is depicted schematically as a heat sink 584 defining a back wall and a separate ring 586 surrounding the chip and additional circuit elements.
- Heat sink 582 thus forms a back wall of the package, whereas ring 586 forms side walls.
- Flexible sheet 510 extends across the front of the package, and overlies ring 586 .
- Ring 586 and heat sink 582 can also be formed integrally with one another to provide a unitary shell.
- the back wall or heat sink 584 has a region 592 confronting the rear surface 590 of the chip.
- a thermally conductive adhesive 594 forms a bond between the rear surface 590 of the chip and region 592 of heat sink 584 , and provides enhanced thermal conductance between the rear surface 590 and the heat sink or back wall.
- Other devices for providing enhanced thermal conductance may be used.
- arrangements of flexible thermal conductors as taught in copending, commonly-assigned U.S. patent application Ser. No. 08/342,222, filed Nov. 18, 1994, the disclosure of which is also incorporated by reference herein, may be employed between the chip and the heat sink.
- fusible conductive masses having properties identical to or substantially similar to those described above may be provided between the rear surface 590 and the heat sink to conduct heat therebetween during operation of the assembly.
- the fusible conductive masses 542 disposed between the contacts are intimately surrounded by a layer of a compliant material 554 .
- the compliant layer 554 may be formed integrally with encapsulant filling the space cooperatively enclosed by the package elements 584 and 586 and sheet 510 .
- chip 522 , sheet 510 and fusible masses 542 may be assembled as discussed above, and additional circuit elements 580 may be assembled to the sheet.
- a first portion of the encapsulant may be introduced into the space between the chip and sheet and cured to form compliant layer 554 while leaving rear surface 590 exposed.
- thermal adhesive 594 and heat sink 582 may be added.
- the reverse process may also be employed, in which the chip is assembled to the heat sink with thermal adhesive 594 , followed by assembly of sheet 510 and masses 542 and formation of layer 554 .
- the assembly can be handled and mounted using ordinary surface-mounting techniques.
- terminals 517 on sheet 510 are bonded to contact pads 564 of a substrate 568 to form the electrical connections between the chip 522 and other components.
- the assembly may be exposed to temperatures in excess of the melting temperature of the conductive masses 642 so that the masses melt. As described above, the resulting liquid masses are contained by the compliant layer 554 . After the surface mounting procedure, the masses are allowed to freeze.
- the assembly may also be exposed to high temperatures during other manufacturing procedures, such as during soldering of substrate 568 to other components; during high-temperature encapsulation processes such as molding or high-temperature curing of an encapsulant around the assembly; or during testing, storage or shipment.
- fusible conductive masses 542 melt and allow movement of terminals 517 relative to the chip.
- masses 542 will melt, but will remain in place to provide a stress-free electrical interconnection as discussed above.
- a process according to a further embodiment of the present invention utilizes a plate 602 of a metal, preferably copper or a copper alloy.
- the metallic plate is large enough to cover an entire wafer; however, only a small portion of the metallic plate is seen in FIG. 11.
- a first surface of the plate is covered by a first resist layer 604 with apertures 606 disposed in locations corresponding to the locations of contacts on a wafer.
- the locations and sizes of apertures 606 can be controlled precisely using conventional photographic techniques for forming resist patterns.
- the second surface of the plate is covered by a uniform layer of a resist 608 . Spots 610 of a barrier metal are then applied on the first surface of the plate in apertures 606 .
- the plate is then exposed to the fusible material in molten form, as by dipping the plate into the molten material; by passing the plate through a flowing curtain or shower of the molten material; or by exposing the first surface of the plate to a wave of molten material using conventional wave-soldering equipment.
- the dipping procedure is preferred. Because the molten material does not wet the resist layers 604 and 608 , but does wet barrier metal 610 , a drop 612 of molten material will cling to the plate at each aperture 606 after the plate is withdrawn from the molten material. The drops freeze to form fusible material masses. Numerous masses can be formed simultaneously at extremely low cost; there is no need for controlled application of the molten material.
- resist layer 604 and 608 are stripped using conventional removal techniques.
- Metallic plate 602 with masses 612 on it, is heated to a temperature sufficient to remelt fusible material 612 and the plate 602 and masses are assembled to a wafer 622 .
- the plate is aligned with the wafer so that each mass 612 is aligned with a contact 624 on the surface of the wafer.
- the fusible conductive masses 612 bonds with the contacts 624 of the wafer. After the bonds have formed, the assembly is cooled to below the melting temperature of the fusible conductive masses, thereby refreezing masses 612 .
- plate 602 is metallic, its thermal expansion properties are quite uniform and isotropic so that the distances between the masses vary in a predictable manner with the temperature of the plate. Moreover, the metal plate resists stretching and compression in directions parallel to its surfaces. These factors greatly facilitate precise alignment of masses 612 with contacts 624 .
- plate 602 can be supported and engaged with the wafer by a press plate, similar to the press plates 50 discussed above with reference to FIG. 1, which supports plate 602 over substantially its entire surface and reinforces plate 602 against bending. However, where plate 602 is thick enough to resist bending, it can be handled and assembled to the wafer using other equipment which does not support the plate over its surface.
- a curable material is injected between plate 602 and wafer 622 and cured to form a compliant material layer 626 intimately surrounding masses 612 .
- an etch-resistant metal such as gold
- the etch-resistant metal can be applied using conventional plating techniques with a conventional photoresist (not shown). After the photoresist is stripped, plate 602 is exposed to an etchant, such as an acid, which removes the plate except in the regions 630 protected by spots 628 .
- an etchant such as an acid
- the etching process thus subdivides the plate into separate regions 630 , leaving each region attached to a mass of fusible conductive material 612 .
- Each region 630 with the overlying metal spot 628 , forms a separate terminal assembly 632 , mechanically decoupled from the other terminal assemblies.
- a further bonding material 634 may be applied on the terminal assemblies, and the wafer may be severed to form individual units, each including one chip and the associated terminal assemblies and fusible masses, together with a portion of the compliant layer.
- the finished unit thus has a microelectronic element 622 ; a layer 626 of a compliant material overlying the microelectronic element, and terminal assemblies 632 disposed on the side of layer 626 opposite from the microelectronic element. Each terminal assembly is connected to a contact 624 on the microelectronic element by a fusible mass 612 .
- the units may be handled, tested and bonded to substrates in the same manner as the units 58 discussed above with reference to FIG. 3.
- the patterned resist 604 (FIG. 11) is replaced by a flexible dielectric sheet 650 (FIG. 15) defining the same pattern of apertures.
- Sheet 650 may be formed from a polymeric material such as a polyimide. The sheet may be formed in situ on the surface of the metal plate, as by coating the surface with a liquid precursor and curing the coating to form the sheet. The polymeric sheet may be provided with the apertures by selectively etching or ablating the sheet using processes which do not substantially affect the underlying metal plate. The remaining steps of the process are conducted in substantially the same way as discussed above with reference to FIGS. 11 - 14 , except that sheet 650 is not removed. Thus, sheet 650 remains during and after the etching process to provide additional protection to the wafer. During the severing step, sheet 650 is severed along with the compliant layer 626 .
- etching step used to subdivide the metallic plate may form numerous posts 655 , each constituting a single terminal assembly associated with one fusible metal mass 612 .
- a continuous metallic plate can be formed into a plurality of posts by applying a photoresist to the exposed surface of the plate and selectively treating the photoresist to leave a pattern of spots covered by etch-resistant regions, and then exposing the surface to an etchant.
- a microelectronic assembly having an array of such posts can be engaged with a mating unit having sockets adapted to engage the posts.
- a different form of terminal assembly also illustrated in FIG. 16, has a solid-core solder ball including a core 660 formed from a high-melting, highly conductive metal such as copper, surrounded by a layer 662 of a solder overlying a region 630 formed by severing the sheet.
- Another form of terminal assembly has a mass of conventional solder 668 overlying each region 630 .
- Yet another terminal assembly has a metal bump 670 formed from gold, copper or other solderable metal on each region.
- the various types of terminal assemblies illustrated in FIG. 16 normally are not found in a single unit; they are illustrated together for ease of comparison.
- each terminal assembly on dielectric sheet or element is disposed on the side of the sheet facing away from the opposite element or chip 622 .
- each terminal assembly defines a contact surface, covered by barrier metal spot 610 , facing toward the opposite element or chip 622 and exposed through an aperture 651 in sheet 650 .
- each fusible conductive mass extends through an aperture in the sheet to the contact surface of the associated terminal assembly.
- one element is a multilayer dielectric sheet 700 with conductors 702 and potential planes 704 disposed in and on the sheet.
- Each terminal assembly includes a metallic via liner 706 extending through the sheet and defining a contact surface on the side of the sheet facing toward the opposite element 722 .
- Each via liner defines a terminal 708 on the surface facing away from the opposite element 722 , and a bonding material 710 may be provided on such terminal surface.
- the contacts and terminals discussed above with reference to FIGS. 1 - 4 may have the configuration illustrated in FIG. 17.
- the fusible materials on each element may be surrounded by partially cured compliant material layers 810 , 812 on each element, and these layers may be united with one another when the elements are brought together, so as to form the compliant material layer surrounding the united fusible conductive masses.
- the compliant layer may be formed in place between the elements, in the manner described above, after uniting the fusible conductive masses.
- each mass may be associated with one or more contacts or terminal assemblies on each element, and each terminal assembly or contact may be associated with one or more fusible masses.
- an assembly according to a further embodiment of the invention includes a chip 1022 connected to the substrate 1068 through fusible material masses 1042 which are again surrounded by a compliant material 1054 .
- Thermal insulation 1070 may be provided around the assembly, particularly in the areas adjacent the fusible masses, so as to assure that the fusible masses reach their melting temperature when the chip is in operation.
- fusible conductive materials other than metals can be employed. These include aqueous and non-aqueous electrolytes. Low-melting conductive compositions including polymeric materials can also be employed. Moreover, the fusible conductive material need not be uniform in composition and need not be entirely molten even at the operating temperature of the device.
- the fusible conductive material may include particles of a first conductive material such as copper, silver or graphite having a high melting temperature dispersed in a second conductive material, such as a low-melting solder or an electrolyte, having a lower melting temperature.
- the second conductive material is liquid but the first conductive material remains solid, so that the fusible material as a whole is in the form of a conductive slurry.
- the term “liquid” should be understood as including a slurry unless otherwise specified.
- the first and second conductive materials should be insoluble in one another and non-reactive with one another.
- the particles of the first conductive material can be plated or otherwise coated with a barrier material as discussed above to inhibit solution and reaction between the particles and the second conductive material.
- the fusible conductive masses melt during normal operation of the assembly.
- the melting temperature of the fusible material is above the normal operating temperature of the microelectronic elements, but below the temperatures encountered by the assembly during manufacturing, storage or shipment.
- the fusible conductive material acts to limit stress applied to the electrical connections due to high temperature exposure in processing steps such as manufacturing, storage or shipment. Indeed, the assembly may be deliberately heated so as to melt the fusible material and thus repair any defects in the masses.
- the melting temperature of the fusible material desirably is below the maximum temperature which can be tolerated by the remainder of the device, so that the assembly can be repaired by heating without removing it from the remainder of the device.
- the elements which are electrically connected to one another need not have confronting surfaces, and the masses of liquid or fusible material need not be physically disposed between the elements.
- a microelectronic element such as a semiconductor chip 1122 may be provided with beam leads 1125 connected to the contacts 1124 of the chip.
- the beam leads project outwardly away from the chip.
- An outboard end of each beam lead, remote from the chip, is embedded in a mass 1142 of a fusible conductive material as discussed above, and electrically connected through such mass to a contact 1164 on a substrate 1168 .
- each beam lead is electrically connected in series with a mass of the fusible conductive material to form an electrical interconnection between the chip and substrate .
- the beam leads and fusible masses are covered by a mass of soft, compliant dielectric encapsulant 1154 which intimately surrounds and protects the fusible masses.
- the contacts 1124 of the chip or first element 1122 are electrically connected to the contacts 1164 of the substrate or second element 1168 .
- the fusible material melts, allowing beam leads 1125 to move relative to the substrate. This action relieves stress on the beam leads and on the connections between the beam leads and the contacts 1124 of the first element.
- the surrounding compliant dielectric material 1154 contains the liquid masses 1124 and maintains them electrically isolated from one another.
- Other physical configurations may be used, provided that the contacts of the elements are electrically connected to one another through masses of liquid or fusible material, and provided that the fusible masses are contained by the surrounding compliant dielectric material.
- the fusible masses may be used in conjunction with flexible leads as taught in the aforementioned U.S. Pat. Nos. 5,148,265; 5,148,266; 5,455,390 and International Publication WO 96/02068, the disclosures of which are hereby incorporated by reference herein.
- a fusible material as referred to herein may serve as a bonding material for connecting the flexible leads as taught in these documents to a microelectronic element.
- an assembly in accordance with a further embodiment of the invention provides a chip package including a rigid panel 1210 such as a conventional fiber reinforced epoxy panel of the type commonly referred to as a “FR-4” circuit board or a ceramic circuit panel; a chip 1222 disposed above the panel and a combined thermal spreader and protective shield 1282 formed from a metal or a metal compound such as aluminum nitride disposed above the chip.
- the chip contacts 1224 are electrically connected to panel contacts 1216 by masses of fusible conductive material 1242 in the manner discussed above. The masses of fusible material are surrounded by a compliant material 1254 forming a layer between the chip and panel.
- Panel contacts 1216 are electrically connected to terminals 1228 by leads on the panel (not shown).
- Terminals 1228 include solder balls for mounting the packaged chip to a larger circuit panel.
- FIG. 23 Yet another embodiment of the invention provides a connector (FIG. 23) similar to that discussed above with reference to FIG. 8 having terminal assemblies similar to those discussed above with reference to FIGS. 14 - 17 on both surfaces.
- the connector thus includes a layer 1354 of compliant material having first terminal assemblies 1332 on a first surface. Each first terminal assembly defines a contact surface 1310 facing toward the compliant layer and a terminal 1328 facing away from the compliant layer.
- second terminal assemblies 1333 on the second surface of layer 1354 define contact surfaces 1311 facing toward the compliant layer and terminals 1329 facing away from the compliant layer.
- Masses 1342 of fusible material extend between the contact surfaces and electrically interconnect each first terminal with a second terminal.
- a connector of this type may be connected between a pair of microelectronic elements to provide an assembly as discussed above.
- the connector can be fabricated by a process as discussed above with reference to FIGS. 12 - 15 , utilizing two metallic plates.
- the fusible masses are provided between the metallic plates, followed by formation of the compliant layer between the plates. After the compliant layer is formed, both metallic plates are subdivided, as by etching, to form the separate terminal assemblies.
- the microelectronic package 1410 includes a first microelectronic element such as a semiconductor chip 1424 which has a generally planar front surface 1426 including electrical parts or contacts 1428 formed on peripheral regions of the front face 1426 .
- a second microelectronic element or circuit element 1412 is provided in the form of a sheet-like dielectric film 1412 having a first surface 1414 and a second surface 1416 .
- the dielectric film 1412 has electrically conductive parts including conductive terminals 1418 . Although terminals 1418 are physically disposed on the first surface 1414 of the sheet, they are accessible at the second surface 1416 for connection through vias 1419 extending through the sheet.
- the second microelectronic element or sheet 1412 overlies the front or contact-bearing surface of chip 1424 , so that these elements define a front space 1434 therebetween.
- a plurality of thermally conductive fusible masses 1422 are disposed in the front space 1434 a .
- a compliant dielectric material fills front space 1434 a , and surrounds masses 1422 as discussed above.
- masses 1422 do not electrically connect the chip with terminals 1418 .
- flexible leads 1420 extending from the terminals 1418 electrically connecting the terminals to the contacts 1428 of the chip. These flexible leads may be provided by conventional processes such as wire bonding, or else may be formed by processes in as shown in U.S. Pat. Nos.
- leads which are initially formed on the flexible sheet.
- the leads may be connected to contacts 1428 before the compliant material is applied in the front space, while fusible masses 1422 are in a solid state and the sheet is supported above the surface of chip 1424 by masses.
- the leads may initially extend across a bond window 1432 in the sheet, and the bond window may be sealed by a mask or coverlay 1436 prior to introduction of the compliant material.
- the semiconductor chip 1424 also has a rear surface 1430 which faces away from the front surface 1426 and faces away from dielectric film 1412 .
- a third microelectronic element 1442 which is a package element, such as a heat sink, is provided.
- Third element or heat sink 1442 includes a back wall 1444 and side walls 1446 forming a unitary shell and surrounding the chip 1424 .
- the dielectric sheet 1412 extends across the front of the heat sink 1442 .
- the heat sink 1442 has a central region 1448 confronting the rear surface 1430 of the chip 1424 .
- the first element or chip 1424 is sandwiched between the second element or dielectric sheet 1412 and the third element—the package element or heat sink 14442 .
- a rear space 1434 b is defined between the surface of central region 1448 of the third element or heat sink 1442 and the rear surface of the first element 1430
- Masses of a fusible conductive material 1450 are disposed in this rear space, between the rear face 1430 of the semiconductor chip 1424 and the central region 1448 of the heat sink 1442 to provide heat or thermal conductance between the chip 1424 and the heat sink 1442 .
- the thermally conductive material incorporated in the masses 1450 comprises an ultra-low melting point solder which is similar to the fusible conductive material described above in reference to FIGS. 1 - 23 .
- Thermally conductive masses 1450 may be positioned in the rear space by depositing them on the surface of the heat sink or on the rear surface of the chip before assembling these elements.
- the heat sink, with the masses thereon in a molten condition may be assembled to the back of the chip. This may be performed before or after assembly of the dielectric sheet or first element and the chip.
- a barrier layer 1452 may be disposed between the rear face 1430 of the semiconductor chip 1424 and the fusible conductive masses 1450 .
- the barrier metal layer 1452 is preferably wettable by the fusible conductive masses 1450 when the latter is in its liquid state.
- the barrier metal may be formed as spots which are coextensive with each fusible conductive mass so that the fusible conductive masses, when in the liquid state, will only wet to the spots.
- the barrier metal may be provided as a contiguous layer which substantially covers the rear face 1430 of the chip 1424 .
- barrier layer 1452 may also act to block alpha radiation from the masses
- the barrier layer composition should be selected to prevent diffusion of the barrier metal into the chip 1424 and/or to prevent contamination of the thermally conductive masses by the material of the chip 1424 . Selection of an appropriate barrier metal will assure that the composition of the fusible conductive masses 1450 will remain essentially unchanged and hence its melting temperature will not vary during continued use of the device. If the material of the heat sink is not compatible with the fusible material, a second barrier layer 1454 may also be disposed between the heat sink 1442 and the fusible conductive masses 1450 to avoid the problems set forth above.
- the fusible conductive masses 1450 and 1422 have been disposed in the front and rear spaces as discussed above, the fusible conductive masses are surrounded by a curable liquid which fills the front space 1434 a and which also fills the rear space 1434 b .
- a single flowable material such as a curable liquid is introduced simultaneously into the front and rear spaces, and forms compliant layers in both of these spaces.
- This material is then cured to form the compliant layers.
- the cured compliant material also extends between the edges of the chip and the side walls 1446 of the package element, so that the compliant material encapsulates the chip 1424 .
- the compliant material desirably also encapsulates the flexible leads 1420 .
- the encapsulant used to form the compliant layer should be capable of flowing, prior to cure, at temperatures below the melting temperature of the fusible conductive masses 1450 and 1422 . To insure complete filling of the spaces by the flowable material, the flowable material may be injected under pressure.
- the assembly described above may be incorporated in an electronic device such as a computer or communications device by connecting the terminals 1418 of the semiconductor package 1410 to contacts 1440 on the substrate 1438 .
- sheet 1412 and particularly terminals 1418 on the sheet desirably are coplanar or substantially coplanar.
- Such planarity can be provided by engaging the sheet or first element 1412 with a planar platen (not shown) and forcing it towards the package element or heat sink 1442 while masses 1422 in the front space, and preferably rear-space masses 1450 as well are in a molten condition. This also causes compression of the compliant materials in the front and rear spaces.
- a planarization process may also occur during bonding of the terminals to a substrate, as during a surface mounting operation.
- the molten masses 1422 and the soft compliant layer allow the terminals and sheet to move into engagement with the contact pads 1440 of the substrate.
- each contact 1428 on the chip 1424 typically moves with respect to the corresponding contact 1440 on the substrate 1438 .
- the chip 1424 , the substrate 1438 or both can warp as they undergo thermal expansion and contraction. Because the terminals 1418 on the dielectric film 1412 are bonded to the contacts 1440 of the substrate 1438 , the dielectric film terminals 1418 will also tend move relative to the contacts 1428 on the chip 1424 .
- the masses 1422 are molten.
- the compliant layer in the front space 1434 a , and the molten masses 1422 can accommodate substantial movement of the chip 1424 relative to the dielectric film 1412 and terminals 1418 without applying high forces between these elements.
- the flexible leads provide electrical interconnection while still permitting such movement.
- Masses 1422 will provide good heat transfer from the chip 1424 to dielectric sheet 1412 and thus to the substrate 1438 . Also, thermal effects will cause movement of chip 1424 relative to the heat sink 1442 .
- the molten thermally conductive masses, in conjunction with the compliant layer in rear space 1434 b will allow such movement while still providing effective heat transfer between the chip and the heat sink.
- the thermally conductive masses 1422 in the front space are omitted.
- a compliant layer may be provided in the front space to mechanically decouple the dielectric sheet 1412 from the chip.
- Such a compliant layer may be formed by providing compliant posts (not shown) on the dielectric sheet to support the sheet on the chip, and injecting a compliant material around these posts, or else may be formed or assembled on the sheet before assembly of the sheet to the chip.
- an assembly and method in accordance with yet further embodiments of the invention provides a multichip module.
- the assembly comprises a first element which includes plural semiconductor chips 1524 a and 1524 b .
- a second element 1512 includes a flexible dielectric sheet having a first surface 1514 facing inwardly toward the chips 1524 and a second surface 1516 facing away from the chips.
- the flexible dielectric sheet 1512 has contacts 1519 on the first surface 1514 , and has terminals 1518 disposed on the second surface 1516 and hence accessible at the second surface.
- the contacts 1519 on the dielectric sheet 1512 are disposed in a pattern corresponding to the pattern of contacts 1528 on the chips 1524 ; however, the contacts 1519 are not integral with the terminals 1518 .
- the terminals 1518 are distributed on the second surface 1516 of the sheet 1512 in an array different from the pattern of contacts 1519 and may occupy a larger area of the sheet 1512 than do the contacts 1519 .
- the terminals 1518 are connected to the contacts 1519 by traces 1520 extending within the sheet 1512 .
- the sheet 1512 may be a multilayer structure, with the traces 1520 disposed between layers as well as on the surfaces of the structure.
- the assembly further includes additional electrical elements 1580 mounted to the sheet 1512 and electrically connected to the leads 1520 , so that the additional elements 1580 are connected between some of the contacts 1519 and the terminals 1518 .
- the additional elements 1580 may include any common circuit element, but most typically include capacitors. The capacitors typically are connected to the terminals 1518 and the contacts 1519 which form the power and ground connections to the chips 1524 . Traces 1520 electrically interconnect chips 1524 a and 1524 b with one another, and with additional electrical elements 1580 .
- the assembly according to this particular embodiment further comprises a third microelectronic element in the form of a package element 1542 which serves to dissipate heat from the chips 1524 as well as to physically support and protect the chips 1524 .
- the package element is depicted schematically as a heat sink 1542 defining a back wall and a separate ring 1546 surrounding the chips 1524 and the additional circuit elements 1580 .
- the dielectric sheet 1512 extends across the front of the package element, and overlies the ring 1546 .
- the heat sink 1542 has a central region 1544 confronting the rear face 1530 of the chips 1524 .
- Masses of a fusible, thermally conductive material 1550 b extend between the rear faces 1530 of the chips 1524 and the central region 1544 for providing thermal conductance between the chips 1524 and the heat sink 1542 .
- the thermally conductive masses 1550 b typically comprise substantially identical materials as described above.
- the thermally conductive masses 1550 b may be larger in diameter than the electrically conductive masses 1550 a , and each thermally conductive mass 1550 b may cover a substantial portion of the rear surface 1530 of the a chip.
- the thermally conductive masses 1550 b may also be surrounded by a compliant layer 1555 which is substantially similar to the compliant layer 1556 surrounding the electrically conductive masses 1550 a .
- the compliant layers between the chips 1524 and the dielectric sheet 1512 and between the rear face 1530 of the chips 1524 and the heat sink 1542 may be formed from the same materials, and both such layers may be formed integrally with the flowable material 1534 filling the space cooperatively enclosed by the heat sink 1542 , the ring 1546 and the dielectric sheet 1512 .
- masses of a fusible, electrically conductive material 1550 a are deposited on the contacts 1528 of the chips 1524 , as described above.
- the dielectric sheet 1512 is assembled to the chips 1524 so that the first surface 1514 of the dielectric sheet 1512 faces toward the front faces 1526 of the chips 1524 and these confronting surfaces define front space 1560 between them.
- the contacts 1519 of the dielectric sheet 1512 are aligned with the contacts 1528 of the chips 1524 and aligned with the electrically conductive masses 1550 a disposed on the chips contacts 1528 .
- the sheet 1512 and the chips 1524 are aligned with one another, the sheet 1512 is pressed toward the chips 1524 so that the exposed surfaces of the contacts 1519 on the first surface 1514 of the sheet 1512 engage the electrically conductive masses 1550 a . While the contacts 1519 and 1528 are held in engagement with the electrically conductive masses 1550 a , the conductive masses 1550 a are brought to a temperature above their melting temperature, so that the conductive material at least partially liquefies and flows into intimate engagement with the exposed surfaces of the contacts 1519 on the dielectric sheet 1512 .
- the sheet 1512 and hence the terminals 1518 are held in a substantially planar condition so that the terminals 1518 on the second surface 1516 of the dielectric sheet 1512 are in substantially coplanar alignment with one another. While the terminals 1518 are aligned in this manner, the electrically conductive masses 1550 a are cooled to below their melting temperature.
- a flowable, preferably liquid material or encapsulant 1534 a is allowed to flow into the front space 1560 between confronting surfaces 1514 and 1526 so that the flowable material 1534 a fills the space 1560 and intimately surrounds the electrically conductive masses 1550 a and the surfaces adjacent contacts 1519 and 1528 .
- the contacts 1519 and the sheet 1512 are maintained in substantially planar disposition, and the contacts 1519 are maintained in alignment with the electrically conductive masses 1550 a .
- the flowable material 1534 a After the front space 1560 has been completely filled by the flowable material 1534 a , the flowable material is cured to form a compliant resilient layer 1556 occupying the space 1560 and intimately surrounding the electrically conductive masses 1550 a and contacts 1519 and 1528 , as described above.
- thermally conductive masses 1550 b and heat sink 1542 are assembled to the rear surfaces of the chips.
- the conductive masses are melted momentarily during the assembly process, so that the thermally conductive masses bond to the rear surfaces of the chips and to the heat sink.
- a further flowable material is added to fill the rear space 1555 between the chip rear surfaces and the heat sink.
- the reverse process may also be employed, in which the chips 1524 are first assembled to the heat sink 1542 and compliant layer 1555 is formed, followed by assembly of the sheet 1512 and the electrically conductive masses 1550 a and formation of compliant layer 1556 between the chips 1524 and the dielectric sheet 1512 .
- the flowable material used to form both front and rear compliant layers may be applied simultaneously.
- the assembly can be handled and mounted using ordinary surface-mounting techniques.
- the terminals 1518 on the dielectric sheet 1512 are bonded to the contacts 1540 on the substrate 1538 to form electrical connections between the chips 1524 and other devices.
- Additional packaging may also be provided around the chips 1524 and the substrate 1538 .
- the chips 1524 and the substrate 1538 may be encapsulated in a flexible encapsulant which may also flow between the dielectric sheet 1512 and the substrate 1538 .
- masses 1550 a and 1550 b melt during operation, and offer essentially resistance to mechanical deformation.
- This compliant layer can accommodate substantial movement of the chips 1524 relative to the dielectric sheet 1512 without applying high forces between these elements.
- the thermally conductive masses 1550 b will melt, but will be contained by the compliant layer 1555 to provide a highly conductive but highly compliant, flexible thermal pathway between the chips 1524 and the heat sink 1542 .
- the device cools and the electrically conductive masses 1550 a and/or the thermally conductive masses 1550 b may freeze again. The cycle of melting and freezing may be repeated numerous times during the service life of the device.
- the melting temperature of the thermally conductive masses 1550 b may be different than that of the electrically conductive masses 1550 a .
- the higher temperature melting masses are placed first and frozen.
- the lower temperature melting masses are then placed and melted while the higher temperature melting masses hold the chips 1524 in position relative to the heat sink 1542 or relative to the dielectric sheet 1512 .
- the flowable material is introduced and cured to form compliant layers 1555 and 1556 simultaneously.
- the flowable material may then be cured to provide a unitary, homogenous compliant layer between the package element and the dielectric sheet.
Abstract
Description
- This is a continuation-in-part of U.S. patent application Ser. No. 08/641,698, filed May 2, 1996, the disclosure of which is hereby incorporated by reference herein.
- The present invention relates to mounting and connection devices and techniques for use with microelectronic elements such as semiconductor chips.
- Complex microelectronic devices such as semiconductor chips require numerous connections to other electronic components. Typically, the microelectronic devices are mounted on substrates or external circuit elements, such as printed circuit boards, having electrical contacts, and the contacts on the chip are electrically connected to the contacts of the external circuit element. The external circuit element may have pins or other connectors adapted to accommodate other components, including additional semiconductor chips. Also, the external circuit element may have pins or other connectors adapted to connect the contacts or internal circuitry of the external circuit element to a larger assembly, thereby connecting the chip to the larger assembly.
- Connections between microelectronic elements and substrates must meet several demanding and often conflicting requirements. They must provide reliable, low-impedance electrical interconnections. They must also withstand stresses caused by thermal effects during manufacturing processes such as soldering. Other thermal effects occur during operation of the device. As the system operates, it evolves heat and the components of the system, including the chip and the substrate expand. When operation ceases, the components cool and contract. When the assembly is heated and cooled during manufacture or in operation, the chip and the substrate expand and contract at different rates, so that portions of the chip and substrate move relative to one another. Also, the chip and the substrate can warp as they are heated and cooled, causing further movement of the chip relative to the substrate. These and other effects cause repeated strain on electrical elements connecting the chip and the substrate. The interconnection system should withstand repeated thermal cycling without breakage of the electrical connections. The interconnection system should provide a compact assembly, and should be suitable for use with components having closely-spaced contacts. Moreover, the interconnection should be economical.
- Various solutions have been proposed to meet these needs. In particular, as disclosed in U.S. Pat. Nos. 5,148,265; 5,148,266; 5,455,390 and in International Publication WO 96/02068, flexible leads may be provided between the contacts on a chip or other microelectronic element and the contact pads of a substrate. According to preferred embodiments taught in these documents, a compliant layer, such as an elastomer or a gel may be provided between the chip and the substrate. Flexible leads connecting the chip and substrate may extend through the compliant layer. In these preferred arrangements, the chip is mechanically decoupled from the substrate, so that the chip and substrate can expand and move independently of one another without excessive stress on the electrical connections between the chip contacts and the contact pads of the substrate. Moreover, the assemblies disclosed in these patents and publications meet the other requirements discussed above. In certain preferred embodiments according to these documents, the chip and the interconnections to the substrate can occupy an area of the substrate about the same size as the chip itself.
- Microelectronic elements such as semiconductor chips generate considerable amounts of heat during use. For example, a complex, high-speed chip only a few centimeters square in area may produce tens of watts of heat. This heat must be dissipated to maintain the chip at a safe operating temperature. Improvements in chip mountings and electrical connections, and in related assembly methods, have made it possible to reduce the distance between chips so as to achieve a more compact assembly. Such assemblies, typically referred to as “multichip modules,” incorporate one or more substrates with chips disposed close to one another on the substrate. The heat dissipation problems discussed above are particularly extreme in such compact multichip modules.
- Considerable effort has been devoted in the art towards meeting these needs for cooling. A general outline of the approaches taken heretofore is set forth in the text Multichip Module Technologies and Alternatives—The Basics, Doane, D. A. and Franzon, P. D., EDS 1993 Van Nostrand Reinhold, New York, N.Y. at
chapter 12, pp. 569-613, entitled “Thermal Design Considerations For Multichip Module Applications” (Azar, K., chapter author) and at pages 109-111 of the same reference. As described therein, heat transfer problems in electronic packaging can be addressed in terms of “thermal resistance” of the elements involved. The thermal resistance of any element in the heat transfer path refers to the ratio between the temperature difference across such element and the rate of heat flow through the element. Thermal insulators have high thermal resistance whereas elements which convey heat effectively by conduction or convection have low thermal resistance. The overall thermal resistance of the package is the sum of the individual thermal resistances in series in the heat path between the chip and the ambient environment. The overall thermal resistance in turn provides a ratio between the temperature rise of the chips above ambient temperature and the amount of heat produced in the chips. - As described in the aforementioned reference, the heat conduction pathway may include an element commonly referred to as a “heat sink.” There is normally a low thermal resistance connection from the heat sink to the environment. For example, the vanes of the heat sink may be bathed in a flow of forced air or liquid. However, there is generally an appreciable thermal resistance between the semiconductor chip, or other microelectronic components, and the heat sink. Stated another way, it is difficult to provide a low thermal resistance connection between the chip and the heat sink while still meeting all of the other requirements for such a connection. This is because the thermal connection must accommodate relative movement between the chips or other components and the heat sink during use of the device. Such relative movement arises in part from movement of the components and the substrate bearing the components as the assembly undergoes temperature changes during use. When the unit is first supplied with power, the temperature of the chips or other components rises faster than the temperature of the substrate, causing differential thermal expansion, warpage and distortion. Further, the coefficients of thermal expansion of the chips and the substrate normally are not matched with the coefficient of thermal expansion of the heat sink, causing further differential thermal expansion and contraction.
- Moreover, the connection between the components and the heat sink should accommodate dimensional tolerances in the components, the substrate and the heat sink itself. For example, the chips themselves may be of different thicknesses. Also, the chips can be supported at different levels above the face of the substrate by solder balls or other mountings. The surfaces of the chips may be tilted from their nominal positions, so that the chip surfaces are out of alignment with the surface of the heat sink. The heat sink itself may not be perfectly flat or parallel to the nominal plane of the chip surfaces. Any elements used to connect the heat sink with the chip or the components should be capable of accommodating these tolerances and misalignments. Considerable efforts have been made in the art heretofore towards satisfying these requirements.
- Nonetheless, still further improvement would be desirable. For example, it would be desirable to provide additional connection components and methods which provide effective mechanical decoupling and high resistance to thermally induced stresses, while also providing low cost and high reliability. It would also be desirable to provide a microelectronic package including improved assemblies and methods for dissipating heat therefrom to minimize thermally induced stresses, while also providing high reliability and low cost.
- One aspect of the present invention provides a method of making a microelectronic assembly including the steps of providing a first microelectronic element, such as a semiconductor chip and a second microelectronic element with confronting spaced-apart surfaces defining a space therebetween and providing one or more masses of a fusible conductive material having a melting temperature below about 150° C. in the space. Next, a flowable liquid material, typically a liquid, is introduced between the confronting surfaces of the first and second microelectronic elements and around the one or more fusible conductive masses. The flowable material is then cured to form a compliant layer disposed between the confronting surfaces of the first and second microelectronic elements and surrounding each of the fusible conductive masses. The one or more conductive masses may be maintained in a substantially solid condition or in a substantially liquid condition when the flowable material is introduced. The fusible conductive masses may also be maintained in either a substantially solid condition or in a substantially liquid condition during the curing step.
- The first microelectronic element preferably is a circuit element such as a semiconductor chip. The second microelectronic element may be a further circuit element such as a dielectric element having conductors thereon, or else may be a package element such as a casing, heat spreader or heat sink. The conductive material is thermally conductive, electrically conductive or both. Where the second microelectronic element is a circuit element, the method desirably includes the step of electrically connecting the first and second elements to one another. For example, the step of providing the masses of fusible conductive material may be performed so that the masses extend between contacts on the confronting surfaces of the first and second microelectronic element, so that the masses electrically interconnect the first and second elements. The conductive masses desirably provide a thermal conduction path between the first and second microelectronic elements. Preferably, the one or more fusible conductive masses are contiguous with both elements, and connect the first and second microelectronic elements to one another.
- Preferably, the fusible conductive masses are contiguous with and are contained by the compliant material, so that the conductive material remains in place when in a liquid state. Thus, the compliant layer keeps the fusible conductive masses separate and electrically insulated from one another. Alternatively or additionally, a polymer coating such as a polyparaxylene coating may be provided over the fusible conductive masses. The polyparaxylene coating is a conformal coating which preferably fully encompasses the fusible conductive masses and desirably extends to the neighboring portions of the confronting surfaces of the first and second microelectronic elements. The coating enhances the electrical isolation of the fusible conductive masses and also protects the masses from contamination, e.g. prevents the fusible conductive material and the compliant layer from diffusing into one another. The polyparaxylene coating can also aid in maintaining the masses in place when the masses are in the liquid state.
- In additional preferred methods according to this aspect of the invention, the step of providing said first and second elements being performed so that said second microelectronic element confronts a front surface of the first microelectronic element and these elements define a front space therebetween, the conductive masses being provided in said front space. A third microelectronic element is provided so that this element confront a rear surface. Thus, the first and third microelectronic elements define a rear space between said rear surface and said third microelectronic element. The first microelectronic element is sandwiched between the second and third microelectronic elements, with front and rear spaces on opposite sides of the first microelectronic element. Methods according to this aspect of the invention desirably include the step of disposing one or more additional fusible conductive masses in the rear space and introducing additional flowable material into said rear space and around said conductive masses in said rear space. Most preferably, this additional flowable material is cured to form a rear compliant layer between the third microelectronic element and said first microelectronic element, said rear compliant layer intimately surrounding said conductive masses in said rear space. The step of introducing a flowable material into the rear space, and the step of introducing a flowable material into the front space can be preformed by simultaneously using a single flowable material.
- A related aspect of the invention provides a microelectronic package comprising a first microelectronic element such as a semiconductor chip operable in a range of operating temperatures. The chip or other microelectronic element has a front face including contacts and a rear surface. A compliant layer is disposed between the confronting surfaces of the first microelectronic element and the package element. Masses of a fusible, thermally conductive material having a melting temperature within or below the range of operating temperatures of the first microelectronic element are also provided between the package element and the first microelectronic element. Each such mass extends adjacent to the confronting surfaces of the first microelectronic element and the package element for transferring heat therebetween during operation of the microelectronic package. The package may also include a second microelectronic element such as a circuit element electrically connected to the first microelectronic element, most preferably a flexible dielectric sheet with terminals thereon, overlying the front face of the first microelectronic element or chip. A compliant layer most preferably is provided between the front face and the second microelectronic element. Here again, masses of a fusible conductive material, preferably a material capable of conducting both electrical signals and heat, are dispersed in the second compliant layer so that the fusible conductive masses are spaced apart from one another in lateral directions parallel to the surfaces of the microelectronic elements. These masses may be disposed between the opposing contacts on the first microelectronic element and the second microelectronic element for electrically interconnecting the first and second microelectronic elements. In the final package the first and second compliant layers are preferably contiguous with one another. The package mechanically isolates the first microelectronic element or chip and effectively decouples it from mechanical stresses and differential thermal expansion, while also providing effective heat transfer from the chip and effective interconnection between the chip and external circuitry.
- The masses of the fusible conductive material used in various aspects of the invention may comprise one or more metals or may comprise a metal alloy and are preferably capable of conducting electrical signals, heat or both. The fusible conductive material preferably has a melting temperature below about 125° C., and in more preferred embodiments the fusible conductive material has a melting temperature below about 65° C. Most preferably the fusible conductive material has a melting temperature between about 25° C. and about 65° C. However, lower melting temperatures can be employed if the production process is altered to accommodate the lower melting temperature. The conductive masses preferably are liquid at temperatures within the range of temperatures encountered during normal operation of microelectronic elements, and may have a melting temperature below the range of operating temperatures of the microelectronic elements. The fusible conductive masses may be in a solid state or a liquid state when the assembly is inactive; however, during operation, the fusible conductive masses may be wholly or partially liquid so that essentially no forces will be transmitted between the microelectronic elements through the conductive masses. Stated another way, the conductive masses in their liquid state have spring constants at or close to zero and do not resist movement of the microelectronic elements relative to one another. Alternatively, the conductive material may be a fusible material which melts at temperatures slightly above the range of temperatures encountered during normal operation. In this case, the assembly relieves mechanical stress in the electrical connections or thermal connections, and repairs defects in the connections, when the assembly is exposed to high temperatures during abnormal operating conditions or during processing operations.
- Preferably, the compliant dielectric layer also allows the microelectronic elements to move relative to one another. Thus, the dielectric layer desirably is formed from an elastomer, gel, foam or other material having relatively low resistance to deformation. Preferred assemblies according to the present invention thus allow electrical signals to pass between microelectronic elements through the fusible conductive masses. In addition, preferred assemblies according to the present invention also allow heat generated by the microelectronic elements to be effectively dissipated through the package and allow the confronting faces of the microelectronic elements to move relative to one another to compensate for movement and distortion during thermal cycling of the package. The compliant connection between the microelectronic elements also helps to compensate for tolerances encountered during manufacturing and can be provided even where each conductor has substantial cross-sectional area. Thus, low resistance, low impedance conductors can be utilized without impairing the flexible connection. Moreover, when the fusible material melts, cracks or other defects in the conductive masses are repaired.
- One or more of the microelectronic elements may include a flexible dielectric sheet having an exterior surface facing away from the other elements and having conductive terminals accessible at the exterior surface. Thus, where the first microelectronic element includes a semiconductor chip, the second element may include a flexible dielectric sheet overlying a surface of the chip and having terminals facing away from the surface of the chip. Thus, the front space lies between the flexible sheet and the chip contact bearing face of the chip. The method may further include the step of forcing the terminals into substantially coplanar disposition while maintaining the masses of fusible conductive material in an at least partially molten condition. Preferably, this step is performed prior to curing the flowable material, either before or after introduction of the flowable material into the space. After the conductive masses have been provided between the confronting surfaces of the chip and the dielectric sheet, the conductive terminals are forced into substantially coplanar alignment with one another as the flowable material is introduced therebetween and the conductive masses are allowed to freeze. Alternatively, the flowable material is introduced between the confronting surfaces before the conductive terminals are forced into substantially coplanar alignment. In certain preferred methods according to this aspect of the invention, the flexible sheet and the chip or other element have contacts on their opposing surfaces. Fusible conductive masses are provided between the opposing contacts to electrically interconnect the chip and the dielectric sheet. Additional fusible conductive masses, aside from those used for electrical interconnection, may be provided between the confronting faces of the chip and the dielectric sheet to provide additional conduct heat therebetween. In an alternative embodiment, the dielectric sheet includes conductive terminals accessible at the exterior surface and flexible leads are used to connect the conductive terminals of the dielectric sheet with the contacts of the semiconductor chip. Fusible conductive masses are provided between the confronting faces of the chip and the dielectric sheet for conducting heat therebetween during operation.
- In methods according to further aspects of the invention, one or more of the microelectronic elements may include a plurality of semiconductor chips. For example, the first microelectronic element may include a unitary wafer incorporating a plurality of semiconductor chips, whereas the second microelectronic element may include a flexible dielectric sheet as described above. Each chip is preferably aligned with a portion of the sheet and the contacts on each chip may be connected by the fusible conductive masses to the terminals in the aligned portion of the sheet. The method according to this aspect of the invention may include the further step of severing individual portions of the sheet and wafer to form individual units, each including one or more chips and the portion of the sheet aligned therewith. The step of providing the microelectronic elements and the fusible conductive masses may include the step of providing the masses attached to contacts on one of the microelectronic elements and then juxtaposing the elements with one another and at least partially melting the masses to thereby bond the masses to the contacts on the other element. For example, where one of the elements is a wafer, the masses may be provided on the wafer, and the wafer may be juxtaposed with the flexible dielectric sheet. In methods according to a further aspect of the invention, the second microelectronic element has electrically conductive traces thereon, and a plurality of chips are electrically connected to the second element, as by connection through conductive masses as discussed above, so that the chips are interconnected to one another to form a multichip module.
- Further methods of making a microelectronic assemblies according to the invention include the steps of providing a metallic plate, juxtaposing the plate with a surface of a microelectronic element and providing one or more masses of a fusible conductive material so that the masses extend in a space between the plate and the microelectronic element, and preferably extend all the way from the plate to the microelectronic element. In a particularly preferred arrangement, the plate is provided with the more masses of a fusible conductive material disposed at predetermined locations on a surface thereof before juxtaposing the plate with the microelectronic element. Methods according to this aspect of the invention desirably include the step of injecting a flowable material between the metallic plate and the microelectronic element and curing the flowable material to form a compliant dielectric layer which intimately surrounds the fusible conductive masses. The predictable, isotropic thermal expansion properties of the metallic plate help to provide precise alignment of the fusible conductive masses with the contacts on the microelectronic element. The metallic plate is then subdivided to form separate portions connected to separate ones of the fusible conductive masses. The microelectronic element according to this particular embodiment may include an array of semiconductor chips or a semiconductor wafer. The metallic plate may be subdivided by etching the plate after the flowable material is cured. After the metallic sheet has been subdivided, the wafer and the compliant layer may be severed to form individual units whereby each unit includes one or more chips. In certain embodiments, the metallic plate with the fusible conductive masses may be provided by forming a layer on a first side of the metallic plate whereby the layer has apertures therein and includes a material, such as a polymer, which is non-wettable by the conductive masses. The first side of the plate is then exposed to the fusible conductive masses while the conductive masses are in a molten condition so that drops of the fusible conductive masses adhere to the metallic plate at the apertures therein. The first side of the plate is preferably exposed to the conductive masses by dipping the metallic plate into a bath of the fusible conductive material. A second side of the metallic plate opposite from the first side thereof may be covered by a protective coating during the exposing step to prevent the second side of the metallic plate from coming into contact with the fusible conductive material.
- Barrier layers, such as a layers of polysilicon, may be provided on surfaces of the microelectronic elements which are in contact with the fusible masses, such as on contacts or on surfaces of package elements. The barrier layer prevents the material in the fusible conductive masses from diffusing into the microelectronic element, the opposing contacts and/or the package element. The barrier metal layer also prevents contamination of the fusible material by the microelectronic element and/or the package element.
- Yet a further embodiment of the invention provides structures which can be used as components in fabrication of microelectronic assemblies. A structure according to this aspect of the present invention includes a layer of a matrix material having top and bottom surfaces extending in lateral directions. One or more masses of a fusible conductive material are dispersed in the layer so that the individual conductive masses are spaced apart from one another in the lateral directions and are separated from one another by the matrix material. The fusible conductive masses preferably include one or more metals and preferably have a melting temperature below about 125° C. and more preferably below about 65° C. In certain embodiments, at least some of the fusible conductive masses extend over a major portion of the distance between the top and bottom surfaces of the layer. In still other embodiments, at least some of the fusible conductive masses extend from the top surface to the bottom surface of the layer to provide a continuous conductive path from the top surface to the bottom surface of the layer. The matrix material is selected from the group consisting of (a) compliant materials having a degradation temperature higher than the melting temperature of the fusible conductive masses and (b)flowable, curable precursor materials. This structure may be provided as a prefabricated structure, without microelectronic elements. The prefabricated structure may be used with one or more microelectronic elements to provide a compliant, thermally conductive connection, and may also be used to provide a compliant electrically conductive connection. The structure may also include one or more removable release layers overlying at least one of the surfaces of the layer of matrix material. The release layer protects the structure from contamination during storage and may be removed from the structure shortly before final assembly of the structure with a microelectronic package. The structure may also include an adhesive overlying at least one of the top and/or bottom surfaces of the matrix layer so that the structure may be easily assembled to the surface(s) of one or more microelectronic elements. Alternatively, the matrix material itself may be capable of bonding to a surface of a microelectronic element. Related aspects of the invention provide assembly methods using such components. For example, a layer as aforesaid may be assembled to one or more semiconductor chips, whereby each semiconductor chip has a surface in engagement with a surface of the layer. Thus, the layer may be applied to a surface of a wafer or to an assemblage of individual chips, and the resulting assembly may be severed to provide individual units including one or more chips and a portion of the layer.
- Other objects and advantages of the present invention will be pointed out in the following detailed description and accompanying drawings.
- FIG. 1 is a fragmentary, diagrammatic sectional view depicting a stage in a manufacturing process according to one embodiment of the invention.
- FIG. 2 is a diagrammatic perspective view depicting a wafer utilized in the process of FIG. 1.
- FIG. 3 is a diagrammatic perspective view depicting a subassembly made by the process of FIG. 1.
- FIG. 4 is a diagrammatic, fragmentary sectional view depicting an assembly made using the subassembly of FIG. 2.
- FIG. 5 is a diagrammatic, sectional view similar to FIG. 4, but depicting a portion of an assembly in accordance with a further embodiment of the invention.
- FIG. 6 is a fragmentary sectional view depicting a component in accordance with yet another embodiment of the invention.
- FIG. 7 is a diagrammatic elevational view of an assembly incorporating the subassembly of FIG. 6.
- FIG. 8 is a diagrammatic perspective view depicting a component in accordance with a further embodiment of the invention.
- FIG. 9 is a fragmentary view on an enlarged scale depicting portions of an assembly in accordance with a further embodiment of the invention.
- FIG. 10 is a diagrammatic sectional view of an assembly in accordance with a further embodiment of the invention.
- FIGS. 11 through 14 are fragmentary diagrammatic sectional views of an assembly during successive stages in a fabrication process in accordance with another embodiment of the invention.
- FIG. 15 is a view similar to FIGS.11-14 but depicting an assembly in accordance with yet another embodiment of the invention.
- FIGS.16 is a fragmentary diagrammatic sectional view depicting elements according to further embodiments of the invention.
- FIG. 17 is a fragmentary diagrammatic-sectional view depicting elements according to yet another embodiment of the invention.
- FIG. 18 is a further fragmentary diagrammatic sectional view depicting elements during a process according to another embodiment of the invention.
- FIG. 19 is a fragmentary diagrammatic sectional view depicting elements according to still another embodiment of the invention.
- FIG. 20 is a diagrammatic sectional view depicting an assembly in accordance with yet another embodiment of the invention.
- FIG. 21 is a diagrammatic, partially cutaway, perspective view depicting an assembly in accordance with yet another embodiment of the invention.
- FIG. 22 is a diagrammatic sectional view depicting an assembly in accordance with yet another embodiment of the invention.
- FIG. 23 is a fragmentary diagrammatic sectional view depicting an assembly in accordance with a further embodiment of the invention.
- FIG. 24 is a diagrammatic sectional view of an assembly in accordance with another embodiment of the invention.
- FIG. 25 is a diagrammatic sectional view of an assembly in accordance with still another embodiment of the present invention.
- An assembly in accordance with one embodiment of the invention includes as a first element a
unitary semiconductor wafer 22 incorporating a large number ofsemiconductor chips 28 disposed side by side. The wafer hasnumerous contacts 24 disposed on its top orfront surface 26. Arear surface 27 is devoid of contacts. Each contact includes a small spot of a metal such as aluminum, gold, copper, zinc or tin. The wafer is formed in the normal fashion, with numerous semiconductor devices within eachchip 28 connected to one another and tocontacts 24 by internal circuitry (not shown) formed within the wafer. The wafer also has narrow strip-like regions 30, commonly referred to as “saw lanes” or “scribe streets” extending betweenadjacent chips 28. - The second element of the assembly includes a flexible, but substantially inextensible
dielectric sheet 10 having afirst surface 12 and asecond surface 14. For example,sheet 10 may be a sheet of polyimide about 25 microns or less thick. Vias are formed throughsheet 10 and filled with a metallic material to form solid via liners orterminal assemblies 15 extending through the sheet at predetermined locations. Each via liner defines acontact 16 at thefirst surface 12 ofsheet 10 and a terminal 17 at the second surface of the sheet. Theterminal assemblies 15 may be formed from any suitable metal which can be conveniently deposited in the vias as, for example, copper and copper alloys. Eachcontact 16 is provided with alayer 18 of a barrier material, such as a polycrystalline silicon, on the exposed face of the contact. The barrier material is selected to resist dissolution in the low-melting fusible conductive metal discussed below, and to prevent difflusion of the underlying material of the contact in the fusible metal. The composition of the barrier layer will depend in part upon the composition of the fusible metal. Metals such as nickel, tungsten, titanium and their alloys normally can be used as barrier layers with typical fusible metals such as ultra-low melting solders of the types discussed below. Thebarrier layer 18 may also include a polycrystalline silicon or polysilicon.Barrier layer 18 need only be thick enough to inhibit dissolution of the underlying metal in thecontact 16. A layer of barrier material about 1 micron thick typically is sufficient. The barrier layer material desirably is wettable by the fusible conductive metal when the fusible conductive metal is in its liquid state. The barrier layer may also include a plurality of layers of different compositions.Terminals 17 have bonding material layers ormasses 20 thereon. Essentially any conventional bonding material can be employed, including conventional solders, conductive polymers, and eutectic bonding materials, also referred to as diffusion-bonding alloys. The bonding material is selected to provide satisfactory connection to the contact pads engaged with the terminals in service, as further discussed below. - In a first step of a process according to one embodiment of the invention,
masses 42 of a fusible conductive material such as an ultra-low melting point solder are deposited on thecontacts 24 ofwafer 22. This step of the process may be performed by conventional equipment and techniques commonly used to deposit solder masses on microelectronic elements. Thus, the masses may be applied individually or, by screening the fusible conductive material onto the surface of the wafer using a mask or screen with perforations corresponding to the contacts, and then removing the mask. The mask may be formed separately from the wafer or may be formed in place on the top surface of the wafer by photolithographic techniques. The mask may be removed from the wafer by mechanically separating the mask and wafer or by dissolving the mask after deposition of the fusible metal. Suitable fluxes may be employed during deposition of the fusible metal on the wafer. The flux may be removed after deposition of the fusible metal. After the fusible metal has been deposited on the contacts of the wafer and the mask has been removed, the fusible metal may be briefly re-melted so as to reflow the fusible metal and bring it into even more intimate contact with the contacts of the wafer. - The melting temperature of the fusible conductive material desirably is within or below the normal operating temperature of the semiconductor elements in the wafer, or only slightly above the normal operating temperature range. The normal, expected range of operating temperatures of the semiconductor elements will depend upon the configuration and composition of the element, and upon the operating environment encountered in service. Typical silicon-based semiconductor elements are designed to operate at about 40°C. to about 85°C. Where the fusible conductive material melts or freezes over a range of temperatures, the term “melting temperature” as used in this disclosure should be understood as referring to the solidus temperature, i.e., the temperature at which the metal begins to melt (when heated slowly) or completes freezing (when cooled slowly). Preferably, the melting temperature of the fusible conductive material is above normal room temperature (20°C.) so that the fusible conductive material can be handled conveniently in solid form during the steps discussed below. Thus, the fusible conductive material desirably has a melting temperature of less than about 150°C., preferably less than about 125°C. and more preferably less than about 100°C. Melting temperatures below about 85°C. are more preferred, and melting temperatures below about 65°C. are even more preferred. The range of melting temperatures between about 25°C. and 65°C. is particularly preferred, and melting temperatures between about 35°C. and about 55°C. are especially preferred. However, lower melting temperatures can be employed if the production process is altered to accommodate the lower melting temperature. For example, where a conductive material which melts at a temperature below room temperature is employed, the conductive material and the adjacent parts can be kept at sub-ambient temperatures during those process steps where the conductive material must remain solid. Conversely, where the operating temperature of the microelectronic elements is higher than the typical ranges mentioned above, higher melting fusible materials can be employed.
- Among the suitable low-melting point solders are the following:
COMPOSITION 1 COMPOSITION 2 ELEMENT WEIGHT % WEIGHT % Sn 18.5 10.5 Bi 45 40 Pb 24 21.5 In 10 20 Cd 9.5 8 Melting 55° C. 50° C. Temperature - Solders having compositions intermediate between the two low-melting point solders illustrated in Table 1 can be used. Other suitable low-melting solders include the solder sold under the trademark Indalloy by the Indium Corporation of America, in Clinton, N.Y. For example, Indalloy Number 8 has a melting point of about 93°C., whereas Indalloy Number 117 has a melting point of about 47°C. Still other low-melting solders include other combinations of metals selected from the group consisting of cadmium, bismuth, tin, lead and indium in various proportions, with or without other metals. Additional fusible metals include mercury and mercury containing alloys.
- In the next stage of the process, the dielectric sheet or
second element 10 is assembled to the wafer orfirst element 22 so that thefirst surface 12 of the sheet faces toward thefront surface 26 of the wafer and these confronting surfaces define aspace 46 between them. Thecontacts 16 of the dielectric sheet or second element are aligned with thecontacts 24 of the first element and aligned withmasses 42 of fusible conductive material disposed on the first element contacts. The alignment between thecontacts 16 of the second element and the fusibleconductive masses 42 need not be perfect. The alignment need only be close enough that eachcontact 16 on the second element touches the correct fusibleconductive mass 42 during the melting step discussed below, and so that eachcontact 16 on the sheet or second element does not touch any other fusibleconductive mass 42. - Processes for aligning a sheet and a wafer are disclosed in commonly owned International Patent Publication WO 96/02068, the disclosure of which is hereby incorporated by reference herein as well as in copending, commonly assigned U.S.
Provisional Patent Application 60/001,718, filed Jul. 31, 1995, and commonly assigned U.S. Provisional Patent Application entitled “Framed Sheet Processing,” filed Oct. 17, 1997, the disclosures of which are also incorporated by reference herein. As disclosed in these applications,sheet 10 can be stretched taut by bonding it to a ring of a material such as aluminum having a coefficient of thermal expansion higher than the coefficient of thermal expansion of the sheet and then heating the assembly. While the assembly is in this taut condition at elevated temperature, the sheet is then bonded to a frame formed from a material such as molybdenum having a coefficient of thermal expansion close to that of the sheet, and the ring is removed. The assembly of the frame and the sheet can then be cooled to room temperature and the sheet will remain taut. The taut sheet can be aligned with wafer using a manually adjustable device such as a micrometer-actuated microscope stage by an operator while the operator observes the sheet and wafer under magnification. The alignment step also can be performed robotically, using generally conventional machine-vision systems. Preferably, both the dielectric sheet and the wafer are provided with fiducial marks to be used as a reference in alignment. These marks are arranged so that when the fiducial marks are aligned with one another, the contacts are also properly aligned. The sheet typically is transparent and hence the fiducial marks on the wafer can be observed through the sheet by a human operator or by a machine vision system. - While the sheet and the wafer are aligned with one another, the sheet is pressed inwardly, toward the wafer so that the exposed surfaces of the contacts on the first or inwardly facing
surface 12 ofsheet 10 engage the fusibleconductive masses 42. This can be accomplished by placing the elements between a pair ofplates 48 and 50 so that a first plate engageswafer 22 on its bottom or outwardly facing surface whereas a second plate engagessheet 14 along its top or outwardly facingsurface 14, and urgingplates 50 and 48 towards one another. Depending upon the configuration ofterminals 17 and the bonding materials thereon,plate 50 may be provided with pockets or recesses corresponding to the terminals. The sheet may be held in engagement withplate 50 by application of vacuum throughports 52 in the plate. Alternatively,plate 50 can be provided with a resilient covering such as a foam on the surface of the plate which engages the sheet surface. In yet another alternative, a rigid stiffening plate (not shown) may be provided betweenplate 50 and the sheet surface. A gas or other fluid may be introduced betweenplate 50 and the stiffening plate so that the fluid pressure urges the stiffening plate and the sheet inwardly, towards the wafer until the stiffening plate and sheet reach a stop (not shown). - While the contacts are held in engagement with the fusible conductive masses, the conductive masses are brought to a temperature above their melting temperature, so that the conductive material at least partially liquefies and flows into intimate engagement with the exposed surfaces of the
contacts 16 on the sheet. This may be accomplished by heating the assemblage after the second element orsheet 10 has been engaged with the wafer and conductive masses. Alternatively, the wafer and the conductive masses may be at a temperature above the melting temperature of the fusible conductive material prior to engagement of the sheet. The sheet and hence thecontacts 16 can also be preheated to a temperature above the melting temperature of the fusible conductive masses before engagement withmasses 42. In yet another alternative, only thesheet 10 andcontacts 16 are at a temperature above the melting temperature of the masses, whereas the masses themselves and the wafer are at a temperature slightly below the melting temperature. In this arrangement, each mass will be only partially melted in the region adjacent themating contact 16 on the sheet. - The molten conductive material wets the
barrier metal 18 on the surfaces ofcontacts 16. A flux may be employed in this step as well. Any flux used in the process may be removed by flushingspace 46 with a suitable solvent and removing the solvent. While the masses are in at least a partially molten condition,plate 50 holds the sheet and hence terminals in a substantially planar condition, with the exposed surfaces of the terminals on the second or outwardly facingsurface 14 of the sheet in substantially coplanar alignment with one another. The plates also maintain the alignment of thecontacts 16 andmasses 42 in horizontal directions, parallel to the opposed surfaces 26 and 12 of the first and second elements. While the elements are aligned in this manner, the conductive masses are cooled to below their melting temperature, as by cooling the entire assemblage, includingplates 50 and 48. If thefusible masses 42 were only partially melted, as where the masses were originally at below-melting temperatures and thecontact 16 were at temperatures above the melting temperature, the partially melted portion of the masses can be cooled by heat transfer to the remaining portions of the mass. - Optionally, a polymer such as a
polyparaxylene coating 43 may be provided over the fusibleconductive masses 42. As shown in the drawings, thepolyparaxylene coating 43 is a conformal coating which fully encompasses the fusibleconductive masses 42 and the adjacent regions of thecontacts dielectric sheet 10 and thewafer 22, and may cover portions of these surfaces as well. Thecoating 43 helps to retain thefusible masses 42 in place when they are in a molten condition and helps preserve the electrical isolation of the fusibleconductive masses 42 from one another. The coating also helps to prevent cross-contamination; the coating prevents the fusible conductive material and the material of the compliant layer from diffusing into one another. The polymeric coating may be provided by a vapor-phase coating process of known type. - After the masses have been completely frozen and after the polymer coating (if used) has been applied, a flowable, preferably liquid material is introduced into
space 46 between confrontingsurfaces masses 42 and the adjacent surfaces ofcontacts surfaces contact 16 andsheet 10 are maintained in substantially planar disposition, and the contacts are maintained in alignment withmasses 42. Alignment and planarity can be maintained by adhesion between thefrozen masses 42 andcontacts 16, without external fixturing at this stage. Preferably, however,plates 48 and 50 of the fixture used during the melting and freezing steps discussed above remain in place. Alternatively, the assemblage of the wafer can be removed from this fixture after freezing and placed into another, similar fixture prior to injection of the flowable material. In either case, the fixtures will help to maintain the coplanarity and alignment during injection of the flowable material. In alternative embodiments, the flowable material may be introduced while the fusible conductive masses are in their liquid state. In this alternative system, the flowable material desirably has relatively low viscosity and is essentially immiscible with the molten fusible conductive material. For example, many organic materials, such as silicone gel components, are immiscible with liquid metals. The surface tension of the liquid fusible material on the opposing contacts tends to maintain the molten masses in place. The flowable material may wet the opposing surfaces of the sheet and wafer, so that flow of the material intospace 46 is aided by capillary action. - After
space 46 has been completely filled by the flowable material, the flowable material is cured to form a compliantresilient layer 54 occupyingspace 46 and intimately surrounding the fusibleconductive masses 42 and contacts. The compliant layer, after curing, should have some resistance to deformation. The compliant layer may be a solid or a gel. The compliant layer may incorporate voids, and indeed may take the form of a solid or gel foam. However, the compliant layer should form substantially continuous surfaces surrounding theconductive material masses 42. Preferably, the compliant material has an elastic modulus less than about 100,000 pounds per square inch, and still lower values of elastic modulus are more preferred. The compliant layer desirably has relatively low resistance to shear betweenopposed surfaces surfaces surfaces compliant layer 54 desirably remains soft and cohesive over a range of temperatures encompassing at least the range from the melting temperature of thefusible conductor material 42 to above the normal operating temperatures of thechips 28 constituting the wafer. The compliant layer desirably retains these properties from about 20°C. or below to about 45° C. or higher. Preferably, the compliant layer retains properties in the aforesaid ranges from about 0°C. or below to about 60°C. or above. Most preferably, the compliant layer retains the desired properties from about −65°C. or below to about 150°C. or above. In an alternative embodiment, the flowable material may be introduced around the fusibleconductive masses 42 when the masses are in a liquid state. Thefusible masses 42 may then be frozen before the flowable material cures or after the flowable material cures. - The flowable material used to form
layer 54 should be capable of flowing, prior to cure, at temperatures below the melting temperature of the fusible conductive material inmasses 42. To assure complete filling ofspace 46 by the flowable material, the flowable material may be injected under pressure. Also,space 46 may be evacuated prior to injection of the flowable material. Techniques for evacuation of a space between a flexible sheet and wafer and for injection of flowable, curable materials into such a space are further disclosed in the aforementioned International Patent Publication 96/02068 and United StatesProvisional Patent Application 60/001,718. Suitable flowable materials for forming the compliant layer include polymer compositions which are initially in the form of liquids but which cure by chemical reaction of their ingredients to form a solid or gel. Among the compositions that can be used are silicones, epoxies and urethanes. Particularly suitable compositions include silicone gels of the type sold under the designation Sylgard 577 Curable Silicone Gel by the Dow-Corning Corporation of Midland, Mich. Other suitable silicon gels are available from the Shin-etsu Corporation and from the General Electric Corporation of Schenectady, N.Y. The reaction-curable material may be provided as two mutually reactive components which are mixed immediately prior to introduction of the material intospace 46 and which react spontaneously with one another at ambient temperature. Other reactive polymer compositions can be activated by application of ultraviolet light. The curing step can also be initiated or accelerated by heating the reactive polymer composition. Some or all of the curing step may entail temperatures above the melting temperature of the fusible material inmasses 42. In this case, it is desirable to maintain alignment of the elements, and maintain planarity of thecontacts 16 on the sheet by holding the assemblage in a fixture during at least the elevated temperature portions of the curing step. - After curing to form the compliant layer,
wafer 22,sheet 10 and thecompliant layer 54 are severed by cutting alongsaw lanes 30, using a saw of the type commonly used for dicing wafers. This subdivides the assemblage into individual units 58 (FIG. 3). Each unit includes onechip 28 as well as a portion ofcompliant layer 54 overlying the chip and a portion ofsheet 10 overlying the chip. Each unit hasterminals 17 with exposedbonding material 20 on the side ofsheet 10 facing away from the chip, and each unit has itscontact 16 connected to the corresponding contacts of the chip by fusibleconductive masses 42. These units can be handled and placed like other surface mountable electronic devices. As seen in FIG. 4,unit 58 can be placed on asubstrate 60.Substrate 60 has internalelectrical circuitry 62 andcontact pads 64 connected to such circuitry and disposed on a surface of the substrate. The outwardly facingsecond surface 14 of flexible layer orsecond element 10 is juxtaposed with the surface of the substrate, so that the exposed surfaces ofterminal 17 andbonding material 20 are engaged withcontact pads 64. In this condition, the assembled parts are brought to an elevated temperature so as to activate thebonding material 20 andbond terminals 17 to contactpads 64 on the substrate. During this elevated-temperature bonding process, the fusibleconductive masses 42 melt. However, the fusible conductive material of each mass is contained by the surrounding compliant layer, as well as by the first element orchip 28 and the second element orflexible sheet 10 and the contacts on these elements. In those embodiments wherepolymer coating 43 is used, the fusibleconductive masses 42 may also be contained by the polymer coating around the masses. Therefore, the fusible conductive material remains in position and maintains electrical continuity betweencontact 16 andcontact 24 on the chip. Whileunit 58 is in this condition,contacts 16 andterminals 17 can be displaced readily relative tochip 28. For example, if the contact pads onsubstrate 60 are out of plane, or ifsubstrate 60 is tilted out of parallelism withchip 28, allterminals 17 can still be brought into engagement withcontact pads 64 without applying destructive forces to the unit. After bonding, the assembly can be cooled, whereupon the flowable material inmasses 42 will freeze. - Typically,
substrate 60 incorporates additional electronic components, such as additional semiconductor chips and other components electrically interconnected withchip 28 through theconductors 62 andcontact pads 64 of the substrate and throughterminals 17,contacts 16 and fusibleconductive masses 42. Alternatively or additionally,substrate 60 may include further connectors such ascontact pads 66 or other devices such as sockets, pins for engagement in sockets, wires or other conventional interconnection devices for connectingcircuitry 62 ofsubstrate 60 with a still larger circuit. The assembly is quite compact; eachunit 58 occupies an area on the surface ofsubstrate 60 about the same size as the area ofchip 42 itself. - The assembly may be incorporated in an electronic device such as a computer, a communications device, or an electronic device associated with a non-electronic machine such as an automobile or an industrial machine. During use of the device, electrical signals pass through the substrate and chip via the contacts and fusible conductive masses. Electrical power is converted to heat in the device, principally in
semiconductor chip 28 and in other electronic elements of the device. The heat raises the temperature of the chip and the surrounding elements. As the temperature of the device rises, the fusibleconductive masses 42 melt and are contained by the surrounding elements of the structure, includingcompliant layer 54, chip orfirst element 28 and the flexible layer orsecond element 10 and thecontacts - As the assembly is heated, each
contact 24 on the chip typically moves with respect to thecorresponding contact 16 of theflexible sheet 10 or second element. Thus, as the temperature of the chip rises, thechip 28 tends to expand, thereby movingcontacts 24 relative to thecontact pads 64 of the substrate. For example, where the chip and substrate are formed from materials having different coefficients of thermal expansion, the contacts on the chip will move relative to the contact pads of the substrate as the entire assembly is heated. Even where the coefficients of thermal expansion are the same, differential movement will occur if the temperature of the chip rises or falls at a different rate than the temperature of the substrate. Also, the chip, the substrate or both can warp as they undergo thermal expansion and contraction. Becauseterminals 17 on the flexible sheet orsecond element 10 are bonded to thecontact pads 64 of the substrate,contacts 16 will also move relative to thecontacts 24 of the chip. However, while the fusible conductive material in each mass 42 is at least partially liquid, the conductive masses have essentially no resistance to deformation. The only mechanical interconnection between the first element orchip 28 and the second element orflexible layer 10, and hence the only mechanical interconnection between the chip andsubstrate 60, is provided by thecompliant layer 54. This compliant layer can accommodate substantial movement of the chip surface relative to the surface of the second element orlayer 10 without applying high forces between these elements. Accordingly, relative movement of thechip contacts 24 andsubstrate contact pads 64 do not apply appreciable forces at the bonds between theterminals 17 of the second element and thecontact pads 64 of the substrate so that the bonds are not subject to thermally-induced fatigue as the system operates. Because the fusibleconductive masses 42 are liquid, they are not subject to fatigue during operation at normal operating temperatures. - When power to the system is turned off, the device cools and the fusible
conductive masses 42 may freeze again. The cycle of melting and freezing may be repeated numerous times during the service life of the device. Defects which may occur inmasses 42 are automatically repaired when the masses melt and freeze. Alternatively, where the device is stored in a relatively warm environment, the conductive material and themasses 42 may remain liquid indefinitely. The metal inbarrier layer 18 ofcontact 16 is selected to prevent dissolution of the base metal of the contact into the molten conductive material. Similarly, thecontacts 24 of the chip are formed from metals which will not dissolve in the fusible conductive material. This assures that the composition of the conductive material will remain essentially unchanged and hence its melting temperature will not vary during continued use of the device.Compliant layer 54 protects the fusible conductive material from contamination and helps to assure reliability of the device. Additional packaging may be provided around the chip and substrate. For example, the chip and substrate may be encapsulated in a flexible encapsulant. The encapsulant may also penetrate betweenlayer 10 andsubstrate 60. Other conventional packaging elements, such as metallic shields or “cans”, heat spreaders and the like may be included in the assembly. As discussed in more detail below, further fusible conductive masses may be provided between the chip or other first microelectronic element and the packaging element to conduct heat for dissipating heat from the assembly. - In a variant of the assembly process discussed above, the
finished unit 58 may be tested by engaging it with a test substrate so as to engage the exposed surface of each terminal 17 with a contact on the test substrate and then operatingchip 28 by applying signals through the terminals. Prior to or during such engagement,unit 58 is heated to a temperature high enough to melt the fusibleconductive masses 42, but not high enough to activate thebonding material 20 on the contacts. This allows thecompliant layer 54 andmasses 42 to deform and hence allows theterminals 17 on the exposed surface of the unit to engage the contacts of the test substrate even where the test substrate and/orterminals 17 are not precisely coplanar. - An assembly according to a further embodiment of the invention (FIG. 5) includes a substantially rigid first element such as a
chip 128 withcontacts 124 on afront surface 126, and also includes a substantially rigid second element such as asubstrate 160 withcontacts 164 on an interior surface. The contact-bearingsurface 126 of the chip overlies the contact-bearing surface of the substrate. Here again, masses of a fusibleconductive material 142 are disposed betweencontacts 124 andcontacts 164.Masses 142 are surrounded by acompliant layer 154 substantially filling the space between the confronting surfaces of the first and second elements and intimately surroundingmasses 142. In this embodiment as well, the contacts are provided with barrier layers to avoid dissolution of the contact metals in the fusible conductive material. Structures according to this embodiment may be fabricated by assembling the first and second elements with the fusible conductive material masses, momentarily melting the masses by heating the assembly and then freezing the masses. These steps may be performed using techniques similar to those used in the so-called controlled collapse chip connection technique, commonly referred to as “C4” bonding. C4 bonding is described in detail in Multi-Chip Module Technologies and Alternatives-the Basics, Doane and Franzon, eds; 1993, pp. 450-476 and 434-446, the disclosure of which is hereby incorporated by reference herein. However, the steps of C4 bonding involving melting of the solder typically would be performed at a far lower temperature in preferred embodiments according to this aspect of the invention than in conventional C4 bonding processes employing ordinary solder. After joining the chip and substrate by C4 bonding,compliant layer 154 is formed by injecting a flowable material as an encapsulant into the space between the confronting surfaces of the chip and substrate and curing the flowable to form a solid, gel or form as discussed above. Assemblies according to this aspect of the present invention provide benefits similar to those discussed above. Once again, at operating temperature, the chip is mechanically connected to the substrate only through thecompliant layer 154.Masses 142 are molten and hence provide essentially no resistance to relative movement between the chip and substrate contacts or between thechip 128 and thesubstrate 160 as a whole. By contrast, in conventional assemblies fabricated by C4 processing, the solder joints remain solid at operating temperature and are subjected to fatigue stresses during thermal cycling. - As illustrated in FIG. 6, a further embodiment of the invention provides a connection component200 including a
compliant layer 254 with afirst surface 253 and asecond surface 255. Holes orcavities 243 extend through the compliant layer. Amass 242 of a fusible conductive material is disposed within each hole orcavity 243. A connection component according to this aspect of the invention, can be fabricated by procedures similar to those discussed above. However, in this instance thefirst element 210 andsecond element 222 are both held in a taut condition and aligned with one another with fusibleconductive masses 242 disposed therebetween. Once again, after the conductive material has been reflowed into contact withcontacts compliant layer 254. Connection components according to this aspect of the invention can be used for interconnecting other microelectronic elements such as a chip and a substrate. Thus, the connection component can be placed between confronting surfaces of an element such as achip 280 and another element such as a substrate 282 (FIG. 7) so thatfirst terminals 260 face the contacts ofchip 280 whereassecond terminals 261 face the contacts ofsubstrate 282. The assemblage is heated to a temperature sufficient to activate the solder orbonding materials conductive material 242 melts, but is retained in position bycompliant layer 254. The compliant layer can bend and compress locally as required during this bonding process, to assure good engagement betweenterminals first terminals 260 and hencecontacts 258 are fixed to the chip, whereassecond terminals 261 and the associatedcontacts 262 are fixed to the substrate. A further encapsulant (not shown) may be introduced betweensheet 222 andchip 280, and betweensheet 222 and the substrate, to fill voids in these regions. In use, the fusibleconductive masses 242 melt and allowcontacts 258, fixed to the chip, to move relative tocontacts 262 on the substrate. - As shown in FIG. 8, a simpler connection component includes a layer of a
matrix material 354 having oppositely directed top andbottom surfaces Masses 342 of a flowable conductive material are disposed within cavities 343. The individual fusible conductive masses are dispersed in the layer of matrix material so that the masses are spaced from one another in the lateral directions and separated from one another by the matrix material. The fusible conductive masses preferably are formed from fusible materials of the types discussed above. Eachmass 342 has an exposed portion 352 at the first surface ofmatrix layer 354 and a similar exposedportion 354 at the second surface. A first removable release liner 357A overlies thetop surface 353 of thelayer 354 and a second release liner 357B overlies thebottom surface 355 of thelayer 354. A thin layer of an adhesive 359 optionally may be provided over thetop surface 353 or thebottom surface 355, as by coating these surfaces before the release liners 357A and 357B are provided and preferably beforemasses 342 are provided. The release liners isolate thelayer 354 and themasses 342 from contaminants during storage. - Components according to this embodiment of the invention can be fabricated by a variety of processes. Thus, the
compliant layer 354 can be injection molded to form cavities 343 and then filled with the flowable conductive material. To facilitate such filling, the interior surfaces of holes 343 may be treated to improve wettability of the compliant material by the conductive material, as by electroless plating of the interior surfaces of the holes. Alternatively, themasses 342 can be placed into a mold and a liquid material may be introduced into the mold and solidified around the masses in the manner discussed above. - Components according to FIG. 8 may be provided, handled and stored separately from the microelectronic elements. These components can be used to interconnect opposed microelectronic elements similar to those shown and described above. In such an assembly process, the component is assembled with one microelectronic element, so that the top or bottom surface of the matrix layer is engaged with the microelectronic element. Where the conductive masses are to provide circuit interconnection, this assembly procedure should be performed so that the conductive masses are engaged with contacts on the microelectronic element. The opposite microelectronic element is engaged with the other surface of the matrix layer in similar fashion. Preferably, the matrix layer is bonded to the surfaces of the microelectronic elements. The adhesive layer provided over the top and
bottom surfaces layer 354 and the microelectronic elements. Alternatively or additionally,compliant layer 354 itself may be arranged to adhere to the surfaces of the mating elements. For example,matrix layer 354 may be formed as a partially cured or “B-stage” material. When the component is engaged between mating elements and heated to meltmasses 342, the partially cured material fully cures and bonds with the surfaces of the mating elements. Once the component is assembled with the opposed microelectronic elements, the contacts on the opposed elements bear on the fusibleconductive masses 342 and help to contain the masses within holes 343. The resulting assembly may have a configuration similar to the assembly of FIG. 5, in that the fusible conductive material bears directly on the contacts of the elements such as a chip and a substrate, and the surfaces ofcompliant layer 354 bear directly on these elements. Separately-formed components as shown in FIG. 8 are particularly useful in providing thermally conductive connections between elements. In this use, the components can be applied to surfaces of microelectronic elements without regard for locations of electrical contacts. In one process, a large component as shown in FIG. 8 is applied to therear surface 27 of a wafer (FIG. 2) before the wafer is severed to separate the individual chips from the wafer. Thus, each severed chip includes a matrix layer conductive masses on its rear surface, which can be used to mount the rear surface on a circuit board or to connect a package element such as a heat spreader or heat sink to the chip. Such a process can be performed in conjunction with processes as discussed above for providing similar masses on the front or contact-bearing surface. - Further embodiments, not shown in the drawings, can incorporate combinations of the features discussed above. For example, a component as depicted in FIG. 8 may include terminal assemblies as depicted in FIGS. 6 and 7 on one or both sides of the compliant layer without the
flexible sheets - One consideration in design is the effect of alpha radiation emitted by the conductive materials. Alpha radiation is known to damage the electronic components incorporated in semiconductor chips and to cause momentary errors in operation of such components. Fusible conductive materials which contain heavy metals typically contain small amounts of radioactive isotopes which emit alpha particles. Several measures may be taken to control the effects of alpha radiation on the underlying chip. One such approach is to limit the amount of alpha particle radiation emitted by controlling the radioactive isotope content of the fusible conductive material. Alternatively or additionally, the physical configuration of the contacts and fusible conductive masses may be selected to limit the effects of alpha radiation. Ordinarily, the contacts themselves provide effective shielding against alpha radiation. Alpha particles normally cannot pass directly through a metallic contact into the underlying electronic components of the chip. For example, as shown in FIG. 9, the alpha radiation emitted by fusible
conductive mass 442 a normally cannot pass directly through contact 424 a. Any deleterious effects of alpha radiation on the chip are caused by alpha particles passing around the edges of the contact along paths such aspath 443. Simply increasing the thickness of contact 424 a limits the effect of such alpha radiation. Because thefusible material mass 442 a is spaced at a substantial distance above the surface ofchip 428, alpha particles passing alongpath 443 and along other paths around the periphery of contact 424 a must pass through a substantial thickness ofcompliant layer 454 so that the compliant material absorbs most of the alpha radiation. Alternatively or additionally, the contact may have a larger diameter than the fusible conductive mass. For example, contact 424 b has a diameter Dc substantially larger than the diameter Dm ofmass 442 b at the juncture of the mass and contact. This assures that any alpha radiation passing around the periphery of the contact will pass along apath 443 b at a relatively low angle to the chip surface. Here again, the length of a straight path from the fusible conductive mass to the chip surface is markedly increased. To assure that the fusible conductive mass remains at or near the center ofcontact 424 b, the contact is provided with a ring of a material which is not wettable by the fusible conductive material. The polyparaxylene coating described above may maintain the fusible conductive mass in place when the mass is in its liquid state. In still further embodiments, the contact or the barrier metal at the surface of the contact adjacent the fusible conductive mass may be non-wettable by the fusible material. A small spot adjacent to center of the contact may be plated with a metal which is wettable by the fusible material. Also, themass 442 b is tapered inwardly towards its central axis in the vertical direction upwardly, away from thecontact 424 b. This further assures a long path length from the mass surface to the chip surface. Such tapered masses can be produced by processes such as that discussed above with reference to FIG. 8. Also, the masses can be tapered by techniques commonly used in the C4 bonding art, as by momentarily movingchip 428 away from themating element 410 while the fusible conductive material is in a molten state. - As shown in FIG. 10, an assembly in accordance with a further embodiment of the invention includes a chip or
first element 522 and asecond element 510 including a flexible multilayer sheet.Sheet 510 hascontacts 516 on a first side facing inwardly, toward the chip or first element, and hasterminals 517 on the opposite, outwardly-facing side. As in the embodiments discussed above,contacts 516 are disposed in a pattern corresponding to the pattern ofcontacts 524 on the chip.Terminals 517 are not integral withcontacts 516. Instead, the terminals are distributed on the outwardly-facing side ofsheet 510 in an array different from the pattern ofcontacts 516. In the depicted embodiment,terminals 517 occupy a larger area of the sheet thancontacts 516.Terminals 517 are connected tocontacts 516 byleads 519 extending withinsheet 510.Sheet 510 may be a multilayer structure, with the leads disposed between layers. The assembly further includes additionalelectrical elements 580 mounted tosheet 510 and electrically connected to leads 519, so that the additional elements are connected between some ofcontacts 516 andterminals 517. The additional elements may include any circuit element, but most typically include capacitors. The capacitors typically are connected to the terminals and contacts which form the power and ground connections to the chip. As in the arrangements discussed above, theelectrical contacts 524 of the first element orchip 522 are connected to thecontacts 516 by fusible, electrically-conductive masses 542. - The assembly further includes a package element adapted to physically support and protect the chip and additional electrical elements. The package element is depicted schematically as a
heat sink 584 defining a back wall and aseparate ring 586 surrounding the chip and additional circuit elements.Heat sink 582 thus forms a back wall of the package, whereasring 586 forms side walls.Flexible sheet 510 extends across the front of the package, and overliesring 586.Ring 586 andheat sink 582 can also be formed integrally with one another to provide a unitary shell. The back wall orheat sink 584 has a region 592 confronting therear surface 590 of the chip. A thermally conductive adhesive 594 forms a bond between therear surface 590 of the chip and region 592 ofheat sink 584, and provides enhanced thermal conductance between therear surface 590 and the heat sink or back wall. Other devices for providing enhanced thermal conductance may be used. For example, arrangements of flexible thermal conductors as taught in copending, commonly-assigned U.S. patent application Ser. No. 08/342,222, filed Nov. 18, 1994, the disclosure of which is also incorporated by reference herein, may be employed between the chip and the heat sink. Alternatively, as further discussed below with reference to FIGS. 24-26, fusible conductive masses having properties identical to or substantially similar to those described above may be provided between therear surface 590 and the heat sink to conduct heat therebetween during operation of the assembly. - As in the embodiments discussed above, the fusible
conductive masses 542 disposed between the contacts are intimately surrounded by a layer of acompliant material 554. Thecompliant layer 554 may be formed integrally with encapsulant filling the space cooperatively enclosed by thepackage elements sheet 510. In fabrication of the assembly,chip 522,sheet 510 andfusible masses 542 may be assembled as discussed above, andadditional circuit elements 580 may be assembled to the sheet. A first portion of the encapsulant may be introduced into the space between the chip and sheet and cured to formcompliant layer 554 while leavingrear surface 590 exposed. After this step,thermal adhesive 594 andheat sink 582 may be added. The reverse process may also be employed, in which the chip is assembled to the heat sink withthermal adhesive 594, followed by assembly ofsheet 510 andmasses 542 and formation oflayer 554. - The assembly can be handled and mounted using ordinary surface-mounting techniques. Here again,
terminals 517 onsheet 510 are bonded to contactpads 564 of a substrate 568 to form the electrical connections between thechip 522 and other components. During the surface mounting procedure, the assembly may be exposed to temperatures in excess of the melting temperature of the conductive masses 642 so that the masses melt. As described above, the resulting liquid masses are contained by thecompliant layer 554. After the surface mounting procedure, the masses are allowed to freeze. The assembly may also be exposed to high temperatures during other manufacturing procedures, such as during soldering of substrate 568 to other components; during high-temperature encapsulation processes such as molding or high-temperature curing of an encapsulant around the assembly; or during testing, storage or shipment. During each such high-temperature exposure, fusibleconductive masses 542 melt and allow movement ofterminals 517 relative to the chip. During operation of the completed assembly,masses 542 will melt, but will remain in place to provide a stress-free electrical interconnection as discussed above. - Referring to FIG. 11, a process according to a further embodiment of the present invention utilizes a
plate 602 of a metal, preferably copper or a copper alloy. The metallic plate is large enough to cover an entire wafer; however, only a small portion of the metallic plate is seen in FIG. 11. A first surface of the plate is covered by a first resistlayer 604 withapertures 606 disposed in locations corresponding to the locations of contacts on a wafer. The locations and sizes ofapertures 606 can be controlled precisely using conventional photographic techniques for forming resist patterns. The second surface of the plate is covered by a uniform layer of a resist 608.Spots 610 of a barrier metal are then applied on the first surface of the plate inapertures 606. After the barrier metal is applied, the plate is then exposed to the fusible material in molten form, as by dipping the plate into the molten material; by passing the plate through a flowing curtain or shower of the molten material; or by exposing the first surface of the plate to a wave of molten material using conventional wave-soldering equipment. The dipping procedure is preferred. Because the molten material does not wet the resistlayers wet barrier metal 610, adrop 612 of molten material will cling to the plate at eachaperture 606 after the plate is withdrawn from the molten material. The drops freeze to form fusible material masses. Numerous masses can be formed simultaneously at extremely low cost; there is no need for controlled application of the molten material. - In the next stage of the process, resist
layer Metallic plate 602, withmasses 612 on it, is heated to a temperature sufficient to remeltfusible material 612 and theplate 602 and masses are assembled to awafer 622. The plate is aligned with the wafer so that each mass 612 is aligned with acontact 624 on the surface of the wafer. The fusibleconductive masses 612 bonds with thecontacts 624 of the wafer. After the bonds have formed, the assembly is cooled to below the melting temperature of the fusible conductive masses, thereby refreezingmasses 612. - Because
plate 602 is metallic, its thermal expansion properties are quite uniform and isotropic so that the distances between the masses vary in a predictable manner with the temperature of the plate. Moreover, the metal plate resists stretching and compression in directions parallel to its surfaces. These factors greatly facilitate precise alignment ofmasses 612 withcontacts 624. During assembly with thewafer 622,plate 602 can be supported and engaged with the wafer by a press plate, similar to thepress plates 50 discussed above with reference to FIG. 1, which supportsplate 602 over substantially its entire surface and reinforcesplate 602 against bending. However, whereplate 602 is thick enough to resist bending, it can be handled and assembled to the wafer using other equipment which does not support the plate over its surface. - Referring to FIG. 13, after
masses 612 have frozen, a curable material is injected betweenplate 602 andwafer 622 and cured to form acompliant material layer 626 intimately surroundingmasses 612. After curing of the compliant material, an etch-resistant metal, such as gold, is applied inspots 628 aligned withmasses 612. The etch-resistant metal can be applied using conventional plating techniques with a conventional photoresist (not shown). After the photoresist is stripped,plate 602 is exposed to an etchant, such as an acid, which removes the plate except in theregions 630 protected byspots 628. During the plating, resist-stripping and etching steps,wafer 622 is protected from chemical contamination by the overlyingcompliant layer 626. - The etching process thus subdivides the plate into
separate regions 630, leaving each region attached to a mass of fusibleconductive material 612. Eachregion 630, with the overlyingmetal spot 628, forms a separateterminal assembly 632, mechanically decoupled from the other terminal assemblies. Afurther bonding material 634 may be applied on the terminal assemblies, and the wafer may be severed to form individual units, each including one chip and the associated terminal assemblies and fusible masses, together with a portion of the compliant layer. The finished unit thus has amicroelectronic element 622; alayer 626 of a compliant material overlying the microelectronic element, andterminal assemblies 632 disposed on the side oflayer 626 opposite from the microelectronic element. Each terminal assembly is connected to acontact 624 on the microelectronic element by afusible mass 612. The units may be handled, tested and bonded to substrates in the same manner as theunits 58 discussed above with reference to FIG. 3. - In a variant of this process, the patterned resist604 (FIG. 11) is replaced by a flexible dielectric sheet 650 (FIG. 15) defining the same pattern of apertures.
Sheet 650 may be formed from a polymeric material such as a polyimide. The sheet may be formed in situ on the surface of the metal plate, as by coating the surface with a liquid precursor and curing the coating to form the sheet. The polymeric sheet may be provided with the apertures by selectively etching or ablating the sheet using processes which do not substantially affect the underlying metal plate. The remaining steps of the process are conducted in substantially the same way as discussed above with reference to FIGS. 11-14, except thatsheet 650 is not removed. Thus,sheet 650 remains during and after the etching process to provide additional protection to the wafer. During the severing step,sheet 650 is severed along with thecompliant layer 626. - Referring to FIG. 16, a great variety of terminal shapes and types may be provided using the processes discussed above. The etching step used to subdivide the metallic plate may form
numerous posts 655, each constituting a single terminal assembly associated with onefusible metal mass 612. The techniques used for forming posts disclosed in copending, commonly-assigned U.S. patent application Ser. No. 08/366,236, filed Dec. 29, 1994, the disclosure of which is hereby incorporated by reference herein. As set forth in said '236 application, a continuous metallic plate can be formed into a plurality of posts by applying a photoresist to the exposed surface of the plate and selectively treating the photoresist to leave a pattern of spots covered by etch-resistant regions, and then exposing the surface to an etchant. As also described in the '236 application, a microelectronic assembly having an array of such posts can be engaged with a mating unit having sockets adapted to engage the posts. - A different form of terminal assembly, also illustrated in FIG. 16, has a solid-core solder ball including a
core 660 formed from a high-melting, highly conductive metal such as copper, surrounded by a layer 662 of a solder overlying aregion 630 formed by severing the sheet. Another form of terminal assembly has a mass ofconventional solder 668 overlying eachregion 630. Yet another terminal assembly has ametal bump 670 formed from gold, copper or other solderable metal on each region. As will be appreciated, the various types of terminal assemblies illustrated in FIG. 16 normally are not found in a single unit; they are illustrated together for ease of comparison. The terminal assemblies on dielectric sheet or element are disposed on the side of the sheet facing away from the opposite element orchip 622. However, each terminal assembly defines a contact surface, covered bybarrier metal spot 610, facing toward the opposite element orchip 622 and exposed through anaperture 651 insheet 650. Thus, each fusible conductive mass extends through an aperture in the sheet to the contact surface of the associated terminal assembly. - In the embodiment of FIG. 17, one element is a
multilayer dielectric sheet 700 withconductors 702 andpotential planes 704 disposed in and on the sheet. Each terminal assembly includes a metallic vialiner 706 extending through the sheet and defining a contact surface on the side of the sheet facing toward theopposite element 722. Each via liner defines a terminal 708 on the surface facing away from theopposite element 722, and abonding material 710 may be provided on such terminal surface. The contacts and terminals discussed above with reference to FIGS. 1-4 may have the configuration illustrated in FIG. 17. - As illustrated in FIG. 18, it may be desirable to form fusible conductive masses by applying a
first mass 800 in contact with the terminal assembly or contact 802 of one element; applying asecond mass 804 in contact with the terminal assembly or contact 806 of the opposite element, and then merging these masses with one another by bringing the elements towards one another while the masses are both liquid or molten.Masses masses masses - As shown in FIG. 19, there need not be one-to-one association between the fusible masses and the terminal assemblies or contacts. Thus, a large terminal assembly or contact904 on one element may be connected to several
fusible masses 912. Conversely, alarge mass 914 may be connected to severalterminal assemblies 905. Thus, each mass may be associated with one or more contacts or terminal assemblies on each element, and each terminal assembly or contact may be associated with one or more fusible masses. - As shown in FIG. 20, an assembly according to a further embodiment of the invention includes a
chip 1022 connected to thesubstrate 1068 throughfusible material masses 1042 which are again surrounded by acompliant material 1054.Thermal insulation 1070 may be provided around the assembly, particularly in the areas adjacent the fusible masses, so as to assure that the fusible masses reach their melting temperature when the chip is in operation. - As will be readily appreciated in light of the foregoing discussion, numerous variations and combinations of the features discussed above can be utilized without departing from the present invention. For example, fusible conductive materials other than metals can be employed. These include aqueous and non-aqueous electrolytes. Low-melting conductive compositions including polymeric materials can also be employed. Moreover, the fusible conductive material need not be uniform in composition and need not be entirely molten even at the operating temperature of the device. For example, the fusible conductive material may include particles of a first conductive material such as copper, silver or graphite having a high melting temperature dispersed in a second conductive material, such as a low-melting solder or an electrolyte, having a lower melting temperature. At the operating temperature of the device, the second conductive material is liquid but the first conductive material remains solid, so that the fusible material as a whole is in the form of a conductive slurry. As used in this disclosure, the term “liquid” should be understood as including a slurry unless otherwise specified. The first and second conductive materials should be insoluble in one another and non-reactive with one another. The particles of the first conductive material can be plated or otherwise coated with a barrier material as discussed above to inhibit solution and reaction between the particles and the second conductive material.
- In the embodiments discussed above, the fusible conductive masses melt during normal operation of the assembly. In a further variant of the invention, the melting temperature of the fusible material is above the normal operating temperature of the microelectronic elements, but below the temperatures encountered by the assembly during manufacturing, storage or shipment. In this variant, the fusible conductive material acts to limit stress applied to the electrical connections due to high temperature exposure in processing steps such as manufacturing, storage or shipment. Indeed, the assembly may be deliberately heated so as to melt the fusible material and thus repair any defects in the masses. Where the assembly is part of a larger device such as a multichip module or circuit board, the melting temperature of the fusible material desirably is below the maximum temperature which can be tolerated by the remainder of the device, so that the assembly can be repaired by heating without removing it from the remainder of the device.
- According to further variants of the invention, the elements which are electrically connected to one another need not have confronting surfaces, and the masses of liquid or fusible material need not be physically disposed between the elements. For example, as shown in FIG. 21, a microelectronic element such as a
semiconductor chip 1122 may be provided with beam leads 1125 connected to thecontacts 1124 of the chip. The beam leads project outwardly away from the chip. An outboard end of each beam lead, remote from the chip, is embedded in amass 1142 of a fusible conductive material as discussed above, and electrically connected through such mass to acontact 1164 on asubstrate 1168. Thus, each beam lead is electrically connected in series with a mass of the fusible conductive material to form an electrical interconnection between the chip and substrate . The beam leads and fusible masses are covered by a mass of soft,compliant dielectric encapsulant 1154 which intimately surrounds and protects the fusible masses. In this embodiment as well, thecontacts 1124 of the chip orfirst element 1122 are electrically connected to thecontacts 1164 of the substrate orsecond element 1168. When the assembly is exposed to high temperatures, the fusible material melts, allowing beam leads 1125 to move relative to the substrate. This action relieves stress on the beam leads and on the connections between the beam leads and thecontacts 1124 of the first element. Here again, the surrounding compliantdielectric material 1154 contains theliquid masses 1124 and maintains them electrically isolated from one another. Other physical configurations may be used, provided that the contacts of the elements are electrically connected to one another through masses of liquid or fusible material, and provided that the fusible masses are contained by the surrounding compliant dielectric material. For example, the fusible masses may be used in conjunction with flexible leads as taught in the aforementioned U.S. Pat. Nos. 5,148,265; 5,148,266; 5,455,390 and International Publication WO 96/02068, the disclosures of which are hereby incorporated by reference herein. Indeed, a fusible material as referred to herein may serve as a bonding material for connecting the flexible leads as taught in these documents to a microelectronic element. - Referring to FIG. 22, an assembly in accordance with a further embodiment of the invention provides a chip package including a
rigid panel 1210 such as a conventional fiber reinforced epoxy panel of the type commonly referred to as a “FR-4” circuit board or a ceramic circuit panel; achip 1222 disposed above the panel and a combined thermal spreader andprotective shield 1282 formed from a metal or a metal compound such as aluminum nitride disposed above the chip. Thechip contacts 1224 are electrically connected topanel contacts 1216 by masses of fusibleconductive material 1242 in the manner discussed above. The masses of fusible material are surrounded by a compliant material 1254 forming a layer between the chip and panel.Further portions 1255 of the compliant material fill the space around the chip, between theshield 1282 and thepanel 1210.Panel contacts 1216, and hence the chip contacts, are electrically connected toterminals 1228 by leads on the panel (not shown).Terminals 1228 include solder balls for mounting the packaged chip to a larger circuit panel. - Yet another embodiment of the invention provides a connector (FIG. 23) similar to that discussed above with reference to FIG. 8 having terminal assemblies similar to those discussed above with reference to FIGS.14-17 on both surfaces. The connector thus includes a
layer 1354 of compliant material having firstterminal assemblies 1332 on a first surface. Each first terminal assembly defines acontact surface 1310 facing toward the compliant layer and a terminal 1328 facing away from the compliant layer. Similarly,second terminal assemblies 1333 on the second surface oflayer 1354 definecontact surfaces 1311 facing toward the compliant layer andterminals 1329 facing away from the compliant layer.Masses 1342 of fusible material extend between the contact surfaces and electrically interconnect each first terminal with a second terminal. A connector of this type may be connected between a pair of microelectronic elements to provide an assembly as discussed above. The connector can be fabricated by a process as discussed above with reference to FIGS. 12-15, utilizing two metallic plates. The fusible masses are provided between the metallic plates, followed by formation of the compliant layer between the plates. After the compliant layer is formed, both metallic plates are subdivided, as by etching, to form the separate terminal assemblies. - Still another embodiment of the present invention provides a microelectronic package as shown in FIG. 24. The
microelectronic package 1410 includes a first microelectronic element such as a semiconductor chip 1424 which has a generally planarfront surface 1426 including electrical parts orcontacts 1428 formed on peripheral regions of thefront face 1426. A second microelectronic element orcircuit element 1412 is provided in the form of a sheet-like dielectric film 1412 having afirst surface 1414 and asecond surface 1416. Thedielectric film 1412 has electrically conductive parts including conductive terminals 1418. Although terminals 1418 are physically disposed on thefirst surface 1414 of the sheet, they are accessible at thesecond surface 1416 for connection throughvias 1419 extending through the sheet. The second microelectronic element orsheet 1412 overlies the front or contact-bearing surface of chip 1424, so that these elements define a front space 1434 therebetween. A plurality of thermally conductivefusible masses 1422, formed from fusible materials as discussed above, are disposed in the front space 1434 a. A compliant dielectric material fills front space 1434 a, and surroundsmasses 1422 as discussed above. However,masses 1422 do not electrically connect the chip with terminals 1418. Ratherflexible leads 1420 extending from the terminals 1418 electrically connecting the terminals to thecontacts 1428 of the chip. These flexible leads may be provided by conventional processes such as wire bonding, or else may be formed by processes in as shown in U.S. Pat. Nos. 5,398,863; 5,390,844; 5,536,909 and 5,491,302, utilizing leads which are initially formed on the flexible sheet. The leads may be connected tocontacts 1428 before the compliant material is applied in the front space, whilefusible masses 1422 are in a solid state and the sheet is supported above the surface of chip 1424 by masses. As discussed in the aforementioned patents, the leads may initially extend across abond window 1432 in the sheet, and the bond window may be sealed by a mask orcoverlay 1436 prior to introduction of the compliant material. - The semiconductor chip1424 also has a
rear surface 1430 which faces away from thefront surface 1426 and faces away fromdielectric film 1412. In order to dissipate heat from the chip 1424, as well as support and protect the chip 1424, a thirdmicroelectronic element 1442 which is a package element, such as a heat sink, is provided. Third element orheat sink 1442 includes aback wall 1444 andside walls 1446 forming a unitary shell and surrounding the chip 1424. Thedielectric sheet 1412 extends across the front of theheat sink 1442. Theheat sink 1442 has acentral region 1448 confronting therear surface 1430 of the chip 1424. Thus, the first element or chip 1424 is sandwiched between the second element ordielectric sheet 1412 and the third element—the package element or heat sink 14442. A rear space 1434 b is defined between the surface ofcentral region 1448 of the third element orheat sink 1442 and the rear surface of thefirst element 1430 Masses of a fusibleconductive material 1450 are disposed in this rear space, between therear face 1430 of the semiconductor chip 1424 and thecentral region 1448 of theheat sink 1442 to provide heat or thermal conductance between the chip 1424 and theheat sink 1442. The thermally conductive material incorporated in themasses 1450 comprises an ultra-low melting point solder which is similar to the fusible conductive material described above in reference to FIGS. 1-23. Thermallyconductive masses 1450 may be positioned in the rear space by depositing them on the surface of the heat sink or on the rear surface of the chip before assembling these elements. For example, the heat sink, with the masses thereon in a molten condition, may be assembled to the back of the chip. This may be performed before or after assembly of the dielectric sheet or first element and the chip. - A
barrier layer 1452, similar to the barrier layers described above, may be disposed between therear face 1430 of the semiconductor chip 1424 and the fusibleconductive masses 1450. Thebarrier metal layer 1452 is preferably wettable by the fusibleconductive masses 1450 when the latter is in its liquid state. The barrier metal may be formed as spots which are coextensive with each fusible conductive mass so that the fusible conductive masses, when in the liquid state, will only wet to the spots. Alternatively, the barrier metal may be provided as a contiguous layer which substantially covers therear face 1430 of the chip 1424. When the barrier metal is formed as a contiguous layer, then a non-wettable solder mask or screen should be employed to contain the masses in place and separate from one another when the masses are in a molten condition.Barrier layer 1452 may also act to block alpha radiation from the masses As discussed above, the barrier layer composition should be selected to prevent diffusion of the barrier metal into the chip 1424 and/or to prevent contamination of the thermally conductive masses by the material of the chip 1424. Selection of an appropriate barrier metal will assure that the composition of the fusibleconductive masses 1450 will remain essentially unchanged and hence its melting temperature will not vary during continued use of the device. If the material of the heat sink is not compatible with the fusible material, asecond barrier layer 1454 may also be disposed between theheat sink 1442 and the fusibleconductive masses 1450 to avoid the problems set forth above. - After the fusible
conductive masses side walls 1446 of the package element, so that the compliant material encapsulates the chip 1424. The compliant material desirably also encapsulates the flexible leads 1420. The encapsulant used to form the compliant layer should be capable of flowing, prior to cure, at temperatures below the melting temperature of the fusibleconductive masses - The assembly described above may be incorporated in an electronic device such as a computer or communications device by connecting the terminals1418 of the
semiconductor package 1410 tocontacts 1440 on thesubstrate 1438. To facilitate such connection,sheet 1412 and particularly terminals 1418 on the sheet desirably are coplanar or substantially coplanar. Such planarity can be provided by engaging the sheet orfirst element 1412 with a planar platen (not shown) and forcing it towards the package element orheat sink 1442 whilemasses 1422 in the front space, and preferably rear-space masses 1450 as well are in a molten condition. This also causes compression of the compliant materials in the front and rear spaces. A planarization process may also occur during bonding of the terminals to a substrate, as during a surface mounting operation. Thus, under the conditions used for surface mounting, themolten masses 1422 and the soft compliant layer allow the terminals and sheet to move into engagement with thecontact pads 1440 of the substrate. - During operation as the assembly is heated and cooled, each
contact 1428 on the chip 1424 typically moves with respect to thecorresponding contact 1440 on thesubstrate 1438. Also, the chip 1424, thesubstrate 1438 or both can warp as they undergo thermal expansion and contraction. Because the terminals 1418 on thedielectric film 1412 are bonded to thecontacts 1440 of thesubstrate 1438, the dielectric film terminals 1418 will also tend move relative to thecontacts 1428 on the chip 1424. At operating temperature, however, themasses 1422 are molten. The compliant layer in the front space 1434 a, and themolten masses 1422 can accommodate substantial movement of the chip 1424 relative to thedielectric film 1412 and terminals 1418 without applying high forces between these elements. The flexible leads provide electrical interconnection while still permitting such movement.Masses 1422 will provide good heat transfer from the chip 1424 todielectric sheet 1412 and thus to thesubstrate 1438. Also, thermal effects will cause movement of chip 1424 relative to theheat sink 1442. The molten thermally conductive masses, in conjunction with the compliant layer in rear space 1434 b will allow such movement while still providing effective heat transfer between the chip and the heat sink. - In an assembly according to a further embodiment of the invention, the thermally
conductive masses 1422 in the front space are omitted. In this case, a compliant layer may be provided in the front space to mechanically decouple thedielectric sheet 1412 from the chip. Such a compliant layer may be formed by providing compliant posts (not shown) on the dielectric sheet to support the sheet on the chip, and injecting a compliant material around these posts, or else may be formed or assembled on the sheet before assembly of the sheet to the chip. - As shown in FIG. 25, an assembly and method in accordance with yet further embodiments of the invention provides a multichip module. The assembly comprises a first element which includes plural semiconductor chips1524 a and 1524 b. A
second element 1512 includes a flexible dielectric sheet having afirst surface 1514 facing inwardly toward thechips 1524 and asecond surface 1516 facing away from the chips. Theflexible dielectric sheet 1512 hascontacts 1519 on thefirst surface 1514, and hasterminals 1518 disposed on thesecond surface 1516 and hence accessible at the second surface. Thecontacts 1519 on thedielectric sheet 1512 are disposed in a pattern corresponding to the pattern ofcontacts 1528 on thechips 1524; however, thecontacts 1519 are not integral with theterminals 1518. Instead, theterminals 1518 are distributed on thesecond surface 1516 of thesheet 1512 in an array different from the pattern ofcontacts 1519 and may occupy a larger area of thesheet 1512 than do thecontacts 1519. Theterminals 1518 are connected to thecontacts 1519 bytraces 1520 extending within thesheet 1512. Thus, thesheet 1512 may be a multilayer structure, with thetraces 1520 disposed between layers as well as on the surfaces of the structure. The assembly further includes additionalelectrical elements 1580 mounted to thesheet 1512 and electrically connected to theleads 1520, so that theadditional elements 1580 are connected between some of thecontacts 1519 and theterminals 1518. Theadditional elements 1580 may include any common circuit element, but most typically include capacitors. The capacitors typically are connected to theterminals 1518 and thecontacts 1519 which form the power and ground connections to thechips 1524.Traces 1520 electrically interconnect chips 1524 a and 1524 b with one another, and with additionalelectrical elements 1580. - The assembly according to this particular embodiment further comprises a third microelectronic element in the form of a
package element 1542 which serves to dissipate heat from thechips 1524 as well as to physically support and protect thechips 1524. The package element is depicted schematically as aheat sink 1542 defining a back wall and aseparate ring 1546 surrounding thechips 1524 and theadditional circuit elements 1580. Thedielectric sheet 1512 extends across the front of the package element, and overlies thering 1546. Theheat sink 1542 has a central region 1544 confronting therear face 1530 of thechips 1524. Masses of a fusible, thermallyconductive material 1550 b extend between the rear faces 1530 of thechips 1524 and the central region 1544 for providing thermal conductance between thechips 1524 and theheat sink 1542. The thermallyconductive masses 1550 b typically comprise substantially identical materials as described above. The thermallyconductive masses 1550 b may be larger in diameter than the electricallyconductive masses 1550 a, and each thermallyconductive mass 1550 b may cover a substantial portion of therear surface 1530 of the a chip. - The thermally
conductive masses 1550 b may also be surrounded by acompliant layer 1555 which is substantially similar to thecompliant layer 1556 surrounding the electricallyconductive masses 1550 a. The compliant layers between thechips 1524 and thedielectric sheet 1512 and between therear face 1530 of thechips 1524 and theheat sink 1542 may be formed from the same materials, and both such layers may be formed integrally with theflowable material 1534 filling the space cooperatively enclosed by theheat sink 1542, thering 1546 and thedielectric sheet 1512. - In one method of manufacture, masses of a fusible, electrically
conductive material 1550 a, such as the ultra-low melting point solder described above, are deposited on thecontacts 1528 of thechips 1524, as described above. In the next stage of the process, thedielectric sheet 1512 is assembled to thechips 1524 so that thefirst surface 1514 of thedielectric sheet 1512 faces toward the front faces 1526 of thechips 1524 and these confronting surfaces definefront space 1560 between them. Thecontacts 1519 of thedielectric sheet 1512 are aligned with thecontacts 1528 of thechips 1524 and aligned with the electricallyconductive masses 1550 a disposed on thechips contacts 1528. - While the
dielectric sheet 1512 and thechips 1524 are aligned with one another, thesheet 1512 is pressed toward thechips 1524 so that the exposed surfaces of thecontacts 1519 on thefirst surface 1514 of thesheet 1512 engage the electricallyconductive masses 1550 a. While thecontacts conductive masses 1550 a, theconductive masses 1550 a are brought to a temperature above their melting temperature, so that the conductive material at least partially liquefies and flows into intimate engagement with the exposed surfaces of thecontacts 1519 on thedielectric sheet 1512. - While the
masses 1550 a are in at least a partially molten condition, thesheet 1512 and hence theterminals 1518 are held in a substantially planar condition so that theterminals 1518 on thesecond surface 1516 of thedielectric sheet 1512 are in substantially coplanar alignment with one another. While theterminals 1518 are aligned in this manner, the electricallyconductive masses 1550 a are cooled to below their melting temperature. - After the electrically
conductive masses 1550 a have been completely frozen, a flowable, preferably liquid material or encapsulant 1534 a is allowed to flow into thefront space 1560 between confrontingsurfaces space 1560 and intimately surrounds the electricallyconductive masses 1550 a and the surfacesadjacent contacts contacts 1519 and thesheet 1512 are maintained in substantially planar disposition, and thecontacts 1519 are maintained in alignment with the electricallyconductive masses 1550 a. After thefront space 1560 has been completely filled by the flowable material 1534 a, the flowable material is cured to form a compliantresilient layer 1556 occupying thespace 1560 and intimately surrounding the electricallyconductive masses 1550 a andcontacts - Next, thermally
conductive masses 1550 b andheat sink 1542 are assembled to the rear surfaces of the chips. Here again, the conductive masses are melted momentarily during the assembly process, so that the thermally conductive masses bond to the rear surfaces of the chips and to the heat sink. After these elements have been added, and preferably after the thermallyconductive masses 1550 b are frozen, a further flowable material is added to fill therear space 1555 between the chip rear surfaces and the heat sink. The reverse process may also be employed, in which thechips 1524 are first assembled to theheat sink 1542 andcompliant layer 1555 is formed, followed by assembly of thesheet 1512 and the electricallyconductive masses 1550 a and formation ofcompliant layer 1556 between thechips 1524 and thedielectric sheet 1512. Here again, the flowable material used to form both front and rear compliant layers may be applied simultaneously. - The assembly can be handled and mounted using ordinary surface-mounting techniques. In one embodiment, the
terminals 1518 on thedielectric sheet 1512 are bonded to the contacts 1540 on the substrate 1538 to form electrical connections between thechips 1524 and other devices. Additional packaging may also be provided around thechips 1524 and the substrate 1538. For example, thechips 1524 and the substrate 1538 may be encapsulated in a flexible encapsulant which may also flow between thedielectric sheet 1512 and the substrate 1538. - In this embodiment as well,
masses chips 1524 and the flexible,dielectric sheet 1512, and hence the only mechanical interconnection between thechips 1524 and substrate 1538, is provided by the compliant layer. This compliant layer can accommodate substantial movement of thechips 1524 relative to thedielectric sheet 1512 without applying high forces between these elements. Similarly, the thermallyconductive masses 1550 b will melt, but will be contained by thecompliant layer 1555 to provide a highly conductive but highly compliant, flexible thermal pathway between thechips 1524 and theheat sink 1542. When power to the system is turned off, the device cools and the electricallyconductive masses 1550 a and/or the thermallyconductive masses 1550 b may freeze again. The cycle of melting and freezing may be repeated numerous times during the service life of the device. - In an alternative embodiment, the melting temperature of the thermally
conductive masses 1550 b may be different than that of the electricallyconductive masses 1550 a. The higher temperature melting masses are placed first and frozen. The lower temperature melting masses are then placed and melted while the higher temperature melting masses hold thechips 1524 in position relative to theheat sink 1542 or relative to thedielectric sheet 1512. After both sets of fusible conductive masses have been frozen, the flowable material is introduced and cured to formcompliant layers - As these and other variations and combinations of the features discussed above can be employed, the foregoing description of the preferred embodiments should be taken by way of illustration rather than by way of limitation of the invention as defined by the claims.
Claims (65)
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Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5148265A (en) | 1990-09-24 | 1992-09-15 | Ist Associates, Inc. | Semiconductor chip assemblies with fan-in leads |
US5590460A (en) | 1994-07-19 | 1997-01-07 | Tessera, Inc. | Method of making multilayer circuit |
US5808874A (en) * | 1996-05-02 | 1998-09-15 | Tessera, Inc. | Microelectronic connections with liquid conductive elements |
SG60102A1 (en) * | 1996-08-13 | 1999-02-22 | Sony Corp | Lead frame semiconductor package having the same and method for manufacturing the same |
DE19646476C2 (en) * | 1996-11-11 | 2002-03-14 | Fraunhofer Ges Forschung | connecting structure |
US6266872B1 (en) * | 1996-12-12 | 2001-07-31 | Tessera, Inc. | Method for making a connection component for a semiconductor chip package |
US6635514B1 (en) * | 1996-12-12 | 2003-10-21 | Tessera, Inc. | Compliant package with conductive elastomeric posts |
US6686015B2 (en) | 1996-12-13 | 2004-02-03 | Tessera, Inc. | Transferable resilient element for packaging of a semiconductor chip and method therefor |
US6294040B1 (en) * | 1996-12-13 | 2001-09-25 | Tessera, Inc. | Transferable resilient element for packaging of a semiconductor chip and method therefor |
US5786635A (en) * | 1996-12-16 | 1998-07-28 | International Business Machines Corporation | Electronic package with compressible heatsink structure |
US6687842B1 (en) | 1997-04-02 | 2004-02-03 | Tessera, Inc. | Off-chip signal routing between multiply-connected on-chip electronic elements via external multiconductor transmission line on a dielectric element |
AU6878398A (en) | 1997-04-02 | 1998-10-22 | Tessera, Inc. | Chip with internal signal routing in external element |
US5994781A (en) * | 1997-05-30 | 1999-11-30 | Tessera, Inc. | Semiconductor chip package with dual layer terminal and lead structure |
US6335222B1 (en) | 1997-09-18 | 2002-01-01 | Tessera, Inc. | Microelectronic packages with solder interconnections |
US6303408B1 (en) | 1998-02-03 | 2001-10-16 | Tessera, Inc. | Microelectronic assemblies with composite conductive elements |
US6324754B1 (en) * | 1998-03-25 | 2001-12-04 | Tessera, Inc. | Method for fabricating microelectronic assemblies |
US6191952B1 (en) * | 1998-04-28 | 2001-02-20 | International Business Machines Corporation | Compliant surface layer for flip-chip electronic packages and method for forming same |
US6575764B1 (en) * | 1998-05-22 | 2003-06-10 | Reipur Technology A/S | Means for providing electrical contact |
US6492201B1 (en) | 1998-07-10 | 2002-12-10 | Tessera, Inc. | Forming microelectronic connection components by electrophoretic deposition |
AU5283399A (en) | 1998-07-15 | 2000-02-07 | Fraunhofer-Gesellschaft Zur Forderung Der Angewandten Forschung E.V. | Method for transferring solder to a device and/or testing the device |
JP2000036518A (en) * | 1998-07-16 | 2000-02-02 | Nitto Denko Corp | Wafer scale package structure and circuit board used for the same |
US6117797A (en) * | 1998-09-03 | 2000-09-12 | Micron Technology, Inc. | Attachment method for heat sinks and devices involving removal of misplaced encapsulant |
US6307160B1 (en) * | 1998-10-29 | 2001-10-23 | Agilent Technologies, Inc. | High-strength solder interconnect for copper/electroless nickel/immersion gold metallization solder pad and method |
US5965945A (en) * | 1998-11-12 | 1999-10-12 | Advanced Micro Devices, Inc. | Graded PB for C4 pump technology |
US8021976B2 (en) * | 2002-10-15 | 2011-09-20 | Megica Corporation | Method of wire bonding over active area of a semiconductor circuit |
US6284570B1 (en) * | 1998-12-28 | 2001-09-04 | Semiconductor Components Industries Llc | Method of manufacturing a semiconductor component from a conductive substrate containing a plurality of vias |
US6543131B1 (en) * | 1999-03-10 | 2003-04-08 | Tessera, Inc. | Microelectronic joining processes with temporary securement |
US6579748B1 (en) * | 1999-05-18 | 2003-06-17 | Sanyu Rec Co., Ltd. | Fabrication method of an electronic component |
KR20020011440A (en) * | 1999-06-17 | 2002-02-08 | 마이클 골위저, 호레스트 쉐퍼 | Electronic component with flexible contact structures and method for the production of said component |
US6245595B1 (en) * | 1999-07-22 | 2001-06-12 | National Semiconductor Corporation | Techniques for wafer level molding of underfill encapsulant |
US6331119B1 (en) * | 1999-12-28 | 2001-12-18 | International Business Machines Corporation | Conductive adhesive having a palladium matrix interface between two metal surfaces |
JP2001217279A (en) * | 2000-02-01 | 2001-08-10 | Mitsubishi Electric Corp | High density mounter |
US6656765B1 (en) * | 2000-02-02 | 2003-12-02 | Amkor Technology, Inc. | Fabricating very thin chip size semiconductor packages |
US6710454B1 (en) | 2000-02-16 | 2004-03-23 | Micron Technology, Inc. | Adhesive layer for an electronic apparatus having multiple semiconductor devices |
US6468891B2 (en) | 2000-02-24 | 2002-10-22 | Micron Technology, Inc. | Stereolithographically fabricated conductive elements, semiconductor device components and assemblies including such conductive elements, and methods |
US6586955B2 (en) | 2000-03-13 | 2003-07-01 | Tessera, Inc. | Methods and structures for electronic probing arrays |
DE10012882C2 (en) | 2000-03-16 | 2002-06-20 | Infineon Technologies Ag | Method and device for applying a semiconductor chip to a carrier element |
US6664621B2 (en) | 2000-05-08 | 2003-12-16 | Tessera, Inc. | Semiconductor chip package with interconnect structure |
US7247932B1 (en) * | 2000-05-19 | 2007-07-24 | Megica Corporation | Chip package with capacitor |
US6303469B1 (en) * | 2000-06-07 | 2001-10-16 | Micron Technology, Inc. | Thin microelectronic substrates and methods of manufacture |
US7214566B1 (en) * | 2000-06-16 | 2007-05-08 | Micron Technology, Inc. | Semiconductor device package and method |
US6534851B1 (en) * | 2000-08-21 | 2003-03-18 | Agere Systems, Inc. | Modular semiconductor substrates |
JP2002076196A (en) * | 2000-08-25 | 2002-03-15 | Nec Kansai Ltd | Chip type semiconductor device and its manufacturing method |
US6614103B1 (en) * | 2000-09-01 | 2003-09-02 | General Electric Company | Plastic packaging of LED arrays |
AU2001297790B2 (en) * | 2000-10-25 | 2006-10-12 | Washington State University Research Foundation | Piezoelectric micro-transducers, methods of use and manufacturing methods for same |
DE10143173A1 (en) | 2000-12-04 | 2002-06-06 | Cascade Microtech Inc | Wafer probe has contact finger array with impedance matching network suitable for wide band |
JP3591458B2 (en) * | 2000-12-15 | 2004-11-17 | 松下電器産業株式会社 | Semiconductor device mounting structure and semiconductor device |
US6621168B2 (en) * | 2000-12-28 | 2003-09-16 | Intel Corporation | Interconnected circuit board assembly and system |
US6396699B1 (en) * | 2001-01-19 | 2002-05-28 | Lsi Logic Corporation | Heat sink with chip die EMC ground interconnect |
US7498196B2 (en) | 2001-03-30 | 2009-03-03 | Megica Corporation | Structure and manufacturing method of chip scale package |
CN1383197A (en) * | 2001-04-25 | 2002-12-04 | 松下电器产业株式会社 | Mfg. method of semiconductor device and semiconductor device |
KR100380107B1 (en) * | 2001-04-30 | 2003-04-11 | 삼성전자주식회사 | Circuit board having a heating means and multichip package having hermetic sealing part |
US6493238B1 (en) * | 2001-04-30 | 2002-12-10 | General Dynamics Information Systems, Inc. | Method and apparatus to compliantly interconnect area grid arrays and printed wiring boards |
JP4103342B2 (en) * | 2001-05-22 | 2008-06-18 | 日立電線株式会社 | Manufacturing method of semiconductor device |
US20030048624A1 (en) * | 2001-08-22 | 2003-03-13 | Tessera, Inc. | Low-height multi-component assemblies |
KR100443399B1 (en) * | 2001-10-25 | 2004-08-09 | 삼성전자주식회사 | Semiconductor package having thermal interface material(TIM) formed void |
JP3891346B2 (en) * | 2002-01-07 | 2007-03-14 | 千住金属工業株式会社 | Fine copper ball and method for producing fine copper ball |
TW529112B (en) * | 2002-01-07 | 2003-04-21 | Advanced Semiconductor Eng | Flip-chip packaging having heat sink member and the manufacturing process thereof |
DE60314026T2 (en) * | 2002-02-19 | 2008-01-31 | Canon K.K. | Luminous intensity regulating element, associated manufacturing method, luminous intensity regulating device and camera |
US20040080033A1 (en) * | 2002-04-09 | 2004-04-29 | Advanced Semiconductor Engineering Inc. | Flip chip assembly and method for producing the same |
US7436058B2 (en) * | 2002-05-09 | 2008-10-14 | Intel Corporation | Reactive solder material |
WO2003101162A2 (en) * | 2002-05-28 | 2003-12-04 | Molex Incorporated | Connector packaging and transport assembly |
US7147367B2 (en) | 2002-06-11 | 2006-12-12 | Saint-Gobain Performance Plastics Corporation | Thermal interface material with low melting alloy |
US6787920B2 (en) * | 2002-06-25 | 2004-09-07 | Intel Corporation | Electronic circuit board manufacturing process and associated apparatus |
US6791839B2 (en) * | 2002-06-25 | 2004-09-14 | Dow Corning Corporation | Thermal interface materials and methods for their preparation and use |
JP3906767B2 (en) * | 2002-09-03 | 2007-04-18 | 株式会社日立製作所 | Electronic control unit for automobile |
WO2004032267A1 (en) * | 2002-10-02 | 2004-04-15 | Hydrogenics Corporation | Corrosion resistant end plate and method for producing same |
US6680532B1 (en) * | 2002-10-07 | 2004-01-20 | Lsi Logic Corporation | Multi chip module |
TWI221664B (en) * | 2002-11-07 | 2004-10-01 | Via Tech Inc | Structure of chip package and process thereof |
US20050012225A1 (en) * | 2002-11-15 | 2005-01-20 | Choi Seung-Yong | Wafer-level chip scale package and method for fabricating and using the same |
US7411792B2 (en) * | 2002-11-18 | 2008-08-12 | Washington State University Research Foundation | Thermal switch, methods of use and manufacturing methods for same |
US6657864B1 (en) * | 2002-12-16 | 2003-12-02 | International Business Machines Corporation | High density thermal solution for direct attach modules |
TWI290757B (en) * | 2002-12-30 | 2007-12-01 | Advanced Semiconductor Eng | Thermal enhance MCM package and the manufacturing method thereof |
DE10261410B4 (en) * | 2002-12-30 | 2008-09-04 | Qimonda Ag | Method for connecting an integrated circuit to a substrate and corresponding circuit arrangement |
US7023707B2 (en) * | 2003-01-30 | 2006-04-04 | Endicott Interconnect Technologies, Inc. | Information handling system |
US7035113B2 (en) * | 2003-01-30 | 2006-04-25 | Endicott Interconnect Technologies, Inc. | Multi-chip electronic package having laminate carrier and method of making same |
US7135780B2 (en) * | 2003-02-12 | 2006-11-14 | Micron Technology, Inc. | Semiconductor substrate for build-up packages |
US7057277B2 (en) * | 2003-04-22 | 2006-06-06 | Industrial Technology Research Institute | Chip package structure |
US7037805B2 (en) * | 2003-05-07 | 2006-05-02 | Honeywell International Inc. | Methods and apparatus for attaching a die to a substrate |
US6921272B2 (en) * | 2003-05-12 | 2005-07-26 | International Business Machines Corporation | Method and apparatus for providing positive contact force in an electrical assembly |
US20090014897A1 (en) * | 2003-05-15 | 2009-01-15 | Kumamoto Technology & Industry Foundation | Semiconductor chip package and method of manufacturing the same |
JP2004363573A (en) * | 2003-05-15 | 2004-12-24 | Kumamoto Technology & Industry Foundation | Semiconductor chip mounted body and its manufacturing method |
US7057404B2 (en) | 2003-05-23 | 2006-06-06 | Sharp Laboratories Of America, Inc. | Shielded probe for testing a device under test |
DE10335111B4 (en) * | 2003-07-31 | 2006-12-28 | Infineon Technologies Ag | Assembly method for a semiconductor device |
US7132746B2 (en) * | 2003-08-18 | 2006-11-07 | Delphi Technologies, Inc. | Electronic assembly with solder-bonded heat sink |
TWI251916B (en) * | 2003-08-28 | 2006-03-21 | Phoenix Prec Technology Corp | Semiconductor assembled heat sink structure for embedding electronic components |
US20070257766A1 (en) * | 2003-11-18 | 2007-11-08 | Richards Robert F | Micro-Transducer and Thermal Switch for Same |
JP4050219B2 (en) * | 2003-11-18 | 2008-02-20 | アルプス電気株式会社 | Manufacturing method of connection device |
US20050127484A1 (en) * | 2003-12-16 | 2005-06-16 | Texas Instruments Incorporated | Die extender for protecting an integrated circuit die on a flip chip package |
DE112004002554T5 (en) | 2003-12-24 | 2006-11-23 | Cascade Microtech, Inc., Beaverton | Active wafer sample |
US20050151243A1 (en) * | 2004-01-12 | 2005-07-14 | Mok Lawrence S. | Semiconductor chip heat transfer |
US7288839B2 (en) * | 2004-02-27 | 2007-10-30 | International Business Machines Corporation | Apparatus and methods for cooling semiconductor integrated circuit package structures |
JP2005259475A (en) * | 2004-03-10 | 2005-09-22 | Jst Mfg Co Ltd | Anisotropic conductive sheet |
US7006353B2 (en) * | 2004-03-11 | 2006-02-28 | International Business Machines Corporation | Apparatus and method for attaching a heat sink to an integrated circuit module |
US20050208700A1 (en) * | 2004-03-19 | 2005-09-22 | Chippac, Inc. | Die to substrate attach using printed adhesive |
DE102004023305A1 (en) * | 2004-04-19 | 2005-11-03 | Siemens Ag | Power semiconductor |
FI20040592A (en) * | 2004-04-27 | 2005-10-28 | Imbera Electronics Oy | Conducting heat from an inserted component |
JP4209369B2 (en) * | 2004-08-26 | 2009-01-14 | アルプス電気株式会社 | FUNCTIONAL DEVICE AND ITS MANUFACTURING METHOD, AND ELECTRONIC DEVICE USING THE FUNCTIONAL DEVICE AND ITS MANUFACTURING METHOD |
JP4445351B2 (en) * | 2004-08-31 | 2010-04-07 | 株式会社東芝 | Semiconductor module |
JP2008512680A (en) | 2004-09-13 | 2008-04-24 | カスケード マイクロテック インコーポレイテッド | Double-sided probing structure |
US20060109631A1 (en) * | 2004-11-02 | 2006-05-25 | Data Device Corporation | Method and apparatus for connecting circuit cards employing a cooling technique to achieve desired temperature thresholds and card alignment |
US7259581B2 (en) * | 2005-02-14 | 2007-08-21 | Micron Technology, Inc. | Method for testing semiconductor components |
JP2008544512A (en) | 2005-06-16 | 2008-12-04 | イムベラ エレクトロニクス オサケユキチュア | Circuit board structure and manufacturing method thereof |
US20070099410A1 (en) * | 2005-10-31 | 2007-05-03 | Sawyer William D | Hard intermetallic bonding of wafers for MEMS applications |
US7491567B2 (en) * | 2005-11-22 | 2009-02-17 | Honeywell International Inc. | MEMS device packaging methods |
US20070114643A1 (en) * | 2005-11-22 | 2007-05-24 | Honeywell International Inc. | Mems flip-chip packaging |
TWI294172B (en) * | 2006-02-21 | 2008-03-01 | Via Tech Inc | Chip package structure and stacked structure of chip package |
TWI296839B (en) * | 2006-03-15 | 2008-05-11 | Advanced Semiconductor Eng | A package structure with enhancing layer and manufaturing the same |
US20100224395A1 (en) * | 2006-03-28 | 2010-09-09 | Panasonic Corporation | Multilayer wiring board and its manufacturing method |
TWI294677B (en) * | 2006-03-31 | 2008-03-11 | Ind Tech Res Inst | Interconnect structure with stress buffering ability and the manufacturing method thereof |
US20070246821A1 (en) * | 2006-04-20 | 2007-10-25 | Lu Szu W | Utra-thin substrate package technology |
US7403028B2 (en) * | 2006-06-12 | 2008-07-22 | Cascade Microtech, Inc. | Test structure and probe for differential signals |
US7764072B2 (en) | 2006-06-12 | 2010-07-27 | Cascade Microtech, Inc. | Differential signal probing system |
US7723999B2 (en) | 2006-06-12 | 2010-05-25 | Cascade Microtech, Inc. | Calibration structures for differential signal probing |
TWI316748B (en) * | 2006-07-17 | 2009-11-01 | Via Tech Inc | Cooling module against esd and electronic package, assembly, and system using the same |
US7804177B2 (en) | 2006-07-26 | 2010-09-28 | Taiwan Semiconductor Manufacturing Company, Ltd. | Silicon-based thin substrate and packaging schemes |
US7582966B2 (en) | 2006-09-06 | 2009-09-01 | Megica Corporation | Semiconductor chip and method for fabricating the same |
TW200820401A (en) * | 2006-10-23 | 2008-05-01 | Via Tech Inc | Chip package and manufacturing method thereof |
US7642793B2 (en) * | 2006-11-22 | 2010-01-05 | Taiwan Semiconductor Manufacturing Company, Ltd. | Ultra-fine pitch probe card structure |
US7791199B2 (en) * | 2006-11-22 | 2010-09-07 | Tessera, Inc. | Packaged semiconductor chips |
US8569876B2 (en) | 2006-11-22 | 2013-10-29 | Tessera, Inc. | Packaged semiconductor chips with array |
US7696766B2 (en) * | 2007-01-31 | 2010-04-13 | Taiwan Semiconductor Manufacturing Company, Ltd. | Ultra-fine pitch probe card structure |
EP2575166A3 (en) * | 2007-03-05 | 2014-04-09 | Invensas Corporation | Chips having rear contacts connected by through vias to front contacts |
US7800916B2 (en) * | 2007-04-09 | 2010-09-21 | Endicott Interconnect Technologies, Inc. | Circuitized substrate with internal stacked semiconductor chips, method of making same, electrical assembly utilizing same and information handling system utilizing same |
DE102007019885B4 (en) * | 2007-04-27 | 2010-11-25 | Wieland-Werke Ag | Heatsink with matrix-structured surface |
TWM324375U (en) * | 2007-05-21 | 2007-12-21 | Universal Scient Ind Co Ltd | Stacked packaging structure for communication module |
DE102007024189A1 (en) * | 2007-05-24 | 2008-11-27 | Robert Bosch Gmbh | Method for producing an electronic assembly |
US20090001576A1 (en) * | 2007-06-29 | 2009-01-01 | Surinder Tuli | Interconnect using liquid metal |
US7733102B2 (en) * | 2007-07-10 | 2010-06-08 | Taiwan Semiconductor Manufacturing Company, Ltd. | Ultra-fine area array pitch probe card |
KR101538648B1 (en) | 2007-07-31 | 2015-07-22 | 인벤사스 코포레이션 | Semiconductor packaging process using through silicon vias |
US8097946B2 (en) * | 2007-10-31 | 2012-01-17 | Sanyo Electric Co., Ltd. | Device mounting board, semiconductor module, and mobile device |
JP2009191185A (en) * | 2008-02-15 | 2009-08-27 | Seiko Epson Corp | Conductive adhesive film, method for manufacturing the same, electronic equipment using the conductive adhesive film, and method for manufacturing the electronic equipment using the conductive adhesive film |
US20100053407A1 (en) * | 2008-02-26 | 2010-03-04 | Tessera, Inc. | Wafer level compliant packages for rear-face illuminated solid state image sensors |
US7939945B2 (en) | 2008-04-30 | 2011-05-10 | Intel Corporation | Electrically conductive fluid interconnects for integrated circuit devices |
JP5316261B2 (en) * | 2009-06-30 | 2013-10-16 | 富士通株式会社 | Multichip module, printed circuit board unit and electronic device |
US8324719B2 (en) * | 2009-08-31 | 2012-12-04 | General Electric Company | Electronic package system |
JP5295932B2 (en) * | 2009-11-02 | 2013-09-18 | 新光電気工業株式会社 | Semiconductor package, evaluation method thereof, and manufacturing method thereof |
US9070679B2 (en) * | 2009-11-24 | 2015-06-30 | Marvell World Trade Ltd. | Semiconductor package with a semiconductor die embedded within substrates |
US8531027B2 (en) * | 2010-04-30 | 2013-09-10 | General Electric Company | Press-pack module with power overlay interconnection |
US8791575B2 (en) | 2010-07-23 | 2014-07-29 | Tessera, Inc. | Microelectronic elements having metallic pads overlying vias |
US8796135B2 (en) | 2010-07-23 | 2014-08-05 | Tessera, Inc. | Microelectronic elements with rear contacts connected with via first or via middle structures |
US9640437B2 (en) * | 2010-07-23 | 2017-05-02 | Tessera, Inc. | Methods of forming semiconductor elements using micro-abrasive particle stream |
US8847380B2 (en) | 2010-09-17 | 2014-09-30 | Tessera, Inc. | Staged via formation from both sides of chip |
US8610259B2 (en) | 2010-09-17 | 2013-12-17 | Tessera, Inc. | Multi-function and shielded 3D interconnects |
KR101059490B1 (en) | 2010-11-15 | 2011-08-25 | 테세라 리써치 엘엘씨 | Conductive pads defined by embedded traces |
US8637968B2 (en) | 2010-12-02 | 2014-01-28 | Tessera, Inc. | Stacked microelectronic assembly having interposer connecting active chips |
US8587126B2 (en) | 2010-12-02 | 2013-11-19 | Tessera, Inc. | Stacked microelectronic assembly with TSVs formed in stages with plural active chips |
US8736066B2 (en) | 2010-12-02 | 2014-05-27 | Tessera, Inc. | Stacked microelectronic assemby with TSVS formed in stages and carrier above chip |
US8610264B2 (en) | 2010-12-08 | 2013-12-17 | Tessera, Inc. | Compliant interconnects in wafers |
JP5573645B2 (en) * | 2010-12-15 | 2014-08-20 | 富士通セミコンダクター株式会社 | Semiconductor device and manufacturing method of semiconductor device |
US8610285B2 (en) | 2011-05-30 | 2013-12-17 | Taiwan Semiconductor Manufacturing Company, Ltd. | 3D IC packaging structures and methods with a metal pillar |
US8664760B2 (en) | 2011-05-30 | 2014-03-04 | Taiwan Semiconductor Manufacturing Company, Ltd. | Connector design for packaging integrated circuits |
US8916781B2 (en) * | 2011-11-15 | 2014-12-23 | Invensas Corporation | Cavities containing multi-wiring structures and devices |
US9425124B2 (en) * | 2012-02-02 | 2016-08-23 | International Business Machines Corporation | Compliant pin fin heat sink and methods |
US9281260B2 (en) * | 2012-03-08 | 2016-03-08 | Infineon Technologies Ag | Semiconductor packages and methods of forming the same |
FI20135113L (en) * | 2013-02-05 | 2014-08-06 | Tellabs Oy | Circuit board system with cooling arrangement |
US9287194B2 (en) * | 2013-03-06 | 2016-03-15 | Taiwan Semiconductor Manufacturing Company, Ltd. | Packaging devices and methods for semiconductor devices |
US9023691B2 (en) | 2013-07-15 | 2015-05-05 | Invensas Corporation | Microelectronic assemblies with stack terminals coupled by connectors extending through encapsulation |
US8883563B1 (en) * | 2013-07-15 | 2014-11-11 | Invensas Corporation | Fabrication of microelectronic assemblies having stack terminals coupled by connectors extending through encapsulation |
US9034696B2 (en) * | 2013-07-15 | 2015-05-19 | Invensas Corporation | Microelectronic assemblies having reinforcing collars on connectors extending through encapsulation |
US9082743B2 (en) | 2013-08-02 | 2015-07-14 | Taiwan Semiconductor Manufacturing Company, Ltd. | 3DIC packages with heat dissipation structures |
US9583415B2 (en) * | 2013-08-02 | 2017-02-28 | Taiwan Semiconductor Manufacturing Company, Ltd. | Packages with thermal interface material on the sidewalls of stacked dies |
EP2860319A1 (en) * | 2013-10-11 | 2015-04-15 | Daw Se | Thermal insulation composite and thermal insulation composite area and wall structure, comprising the thermal insulation composite or the thermal insulation composite area, and method for the preparation of wall structures |
CN203707402U (en) * | 2013-12-05 | 2014-07-09 | 番禺得意精密电子工业有限公司 | Electric connector |
US9820384B2 (en) * | 2013-12-11 | 2017-11-14 | Intel Corporation | Flexible electronic assembly method |
US9826662B2 (en) * | 2013-12-12 | 2017-11-21 | General Electric Company | Reusable phase-change thermal interface structures |
US9425114B2 (en) * | 2014-03-28 | 2016-08-23 | Oracle International Corporation | Flip chip packages |
US9214454B2 (en) | 2014-03-31 | 2015-12-15 | Invensas Corporation | Batch process fabrication of package-on-package microelectronic assemblies |
DE102017207329A1 (en) * | 2017-05-02 | 2018-11-08 | Siemens Aktiengesellschaft | Electronic assembly with a built between two substrates component and method for its preparation |
US10515912B2 (en) | 2017-09-24 | 2019-12-24 | Intel Corporation | Integrated circuit packages |
Family Cites Families (63)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2734154A (en) * | 1953-07-27 | 1956-02-07 | Semiconductor devices | |
SU586519A1 (en) * | 1976-06-02 | 1977-12-30 | Предприятие П/Я В-2098 | Electric contact |
US4034468A (en) * | 1976-09-03 | 1977-07-12 | Ibm Corporation | Method for making conduction-cooled circuit package |
US4034469A (en) * | 1976-09-03 | 1977-07-12 | Ibm Corporation | Method of making conduction-cooled circuit package |
US4172907A (en) * | 1977-12-29 | 1979-10-30 | Honeywell Information Systems Inc. | Method of protecting bumped semiconductor chips |
US4299715A (en) * | 1978-04-14 | 1981-11-10 | Whitfield Fred J | Methods and materials for conducting heat from electronic components and the like |
US4473113A (en) * | 1978-04-14 | 1984-09-25 | Whitfield Fred J | Methods and materials for conducting heat from electronic components and the like |
US4466483A (en) * | 1978-04-14 | 1984-08-21 | Whitfield Fred J | Methods and means for conducting heat from electronic components and the like |
US4233645A (en) * | 1978-10-02 | 1980-11-11 | International Business Machines Corporation | Semiconductor package with improved conduction cooling structure |
US4323914A (en) * | 1979-02-01 | 1982-04-06 | International Business Machines Corporation | Heat transfer structure for integrated circuit package |
US4254431A (en) * | 1979-06-20 | 1981-03-03 | International Business Machines Corporation | Restorable backbond for LSI chips using liquid metal coated dendrites |
JPS56134404A (en) * | 1980-03-24 | 1981-10-21 | Sony Corp | Conductive material and method of prdoducing same |
JPS57107501A (en) * | 1980-12-25 | 1982-07-05 | Sony Corp | Conduction material |
US4607277A (en) * | 1982-03-16 | 1986-08-19 | International Business Machines Corporation | Semiconductor assembly employing noneutectic alloy for heat dissipation |
JPS62105379A (en) * | 1985-11-01 | 1987-05-15 | 株式会社日立製作所 | Connector |
FR2634318B1 (en) * | 1988-07-13 | 1992-02-21 | Commissariat Energie Atomique | METHOD FOR MANUFACTURING AN INTEGRATED MEMORY CELL |
US4915167A (en) * | 1988-08-05 | 1990-04-10 | Westinghouse Electric Corp. | Thermal coupling to enhance heat transfer |
CA2002213C (en) * | 1988-11-10 | 1999-03-30 | Iwona Turlik | High performance integrated circuit chip package and method of making same |
US5031308A (en) * | 1988-12-29 | 1991-07-16 | Japan Radio Co., Ltd. | Method of manufacturing multilayered printed-wiring-board |
US5071787A (en) * | 1989-03-14 | 1991-12-10 | Kabushiki Kaisha Toshiba | Semiconductor device utilizing a face-down bonding and a method for manufacturing the same |
US5131582A (en) * | 1989-06-30 | 1992-07-21 | Trustees Of Boston University | Adhesive metallic alloys and methods of their use |
US4966142A (en) * | 1989-06-30 | 1990-10-30 | Trustees Of Boston University | Method for electrically joining superconductors to themselves, to normal conductors, and to semi-conductors |
US5198189A (en) * | 1989-08-03 | 1993-03-30 | International Business Machines Corporation | Liquid metal matrix thermal paste |
DE4027169C2 (en) | 1989-08-31 | 1994-05-05 | Aisin Seiki | Exterior rear-view mirror for a motor vehicle |
US5056706A (en) * | 1989-11-20 | 1991-10-15 | Microelectronics And Computer Technology Corporation | Liquid metal paste for thermal and electrical connections |
US5074947A (en) * | 1989-12-18 | 1991-12-24 | Epoxy Technology, Inc. | Flip chip technology using electrically conductive polymers and dielectrics |
US5164566A (en) * | 1990-06-12 | 1992-11-17 | Microelectronics And Computer Technology Corp. | Method and apparatus for fluxless solder reflow |
DE4019091A1 (en) * | 1990-06-15 | 1991-12-19 | Battelle Institut E V | HEAT DISCHARGE DEVICE FOR SEMICONDUCTOR COMPONENTS AND METHOD FOR THE PRODUCTION THEREOF |
US5097387A (en) * | 1990-06-27 | 1992-03-17 | Digital Equipment Corporation | Circuit chip package employing low melting point solder for heat transfer |
US5819406A (en) * | 1990-08-29 | 1998-10-13 | Canon Kabushiki Kaisha | Method for forming an electrical circuit member |
US5086558A (en) * | 1990-09-13 | 1992-02-11 | International Business Machines Corporation | Direct attachment of semiconductor chips to a substrate with a substrate with a thermoplastic interposer |
US5148266A (en) * | 1990-09-24 | 1992-09-15 | Ist Associates, Inc. | Semiconductor chip assemblies having interposer and flexible lead |
US5148265A (en) * | 1990-09-24 | 1992-09-15 | Ist Associates, Inc. | Semiconductor chip assemblies with fan-in leads |
US5679977A (en) * | 1990-09-24 | 1997-10-21 | Tessera, Inc. | Semiconductor chip assemblies, methods of making same and components for same |
US5037312A (en) * | 1990-11-15 | 1991-08-06 | Amp Incorporated | Conductive gel area array connector |
US5148141A (en) * | 1991-01-03 | 1992-09-15 | Gould Inc. | Fuse with thin film fusible element supported on a substrate |
US5170930A (en) * | 1991-11-14 | 1992-12-15 | Microelectronics And Computer Technology Corporation | Liquid metal paste for thermal and electrical connections |
US5859470A (en) * | 1992-11-12 | 1999-01-12 | International Business Machines Corporation | Interconnection of a carrier substrate and a semiconductor device |
US5328087A (en) * | 1993-03-29 | 1994-07-12 | Microelectronics And Computer Technology Corporation | Thermally and electrically conductive adhesive material and method of bonding with same |
US5445308A (en) * | 1993-03-29 | 1995-08-29 | Nelson; Richard D. | Thermally conductive connection with matrix material and randomly dispersed filler containing liquid metal |
US5459352A (en) * | 1993-03-31 | 1995-10-17 | Unisys Corporation | Integrated circuit package having a liquid metal-aluminum/copper joint |
US5323294A (en) * | 1993-03-31 | 1994-06-21 | Unisys Corporation | Liquid metal heat conducting member and integrated circuit package incorporating same |
US5410449A (en) * | 1993-05-24 | 1995-04-25 | Delco Electronics Corp. | Heatsink conductor solder pad |
KR0171438B1 (en) | 1993-09-29 | 1999-10-15 | 모리시따 요오이찌 | Method for mounting a semiconductor device on a circuit board, and a circuit board with a semiconductor device mounted thereon |
US5367435A (en) * | 1993-11-16 | 1994-11-22 | International Business Machines Corporation | Electronic package structure and method of making same |
US5455390A (en) * | 1994-02-01 | 1995-10-03 | Tessera, Inc. | Microelectronics unit mounting with multiple lead bonding |
WO1995025341A1 (en) * | 1994-03-15 | 1995-09-21 | Irvine Sensors Corporation | 3d stack of ic chips having leads reached by vias through passivation covering access plane |
US5418141A (en) * | 1994-05-06 | 1995-05-23 | Avocet Medical, Inc. | Test articles for performing dry reagent prothrombin time assays |
US5798286A (en) * | 1995-09-22 | 1998-08-25 | Tessera, Inc. | Connecting multiple microelectronic elements with lead deformation |
US5518964A (en) * | 1994-07-07 | 1996-05-21 | Tessera, Inc. | Microelectronic mounting with multiple lead deformation and bonding |
US6499216B1 (en) * | 1994-07-07 | 2002-12-31 | Tessera, Inc. | Methods and structures for electronic probing arrays |
US6361959B1 (en) * | 1994-07-07 | 2002-03-26 | Tessera, Inc. | Microelectronic unit forming methods and materials |
US5557501A (en) * | 1994-11-18 | 1996-09-17 | Tessera, Inc. | Compliant thermal connectors and assemblies incorporating the same |
US5542602A (en) * | 1994-12-30 | 1996-08-06 | International Business Machines Corporation | Stabilization of conductive adhesive by metallurgical bonding |
US5572404A (en) * | 1995-09-21 | 1996-11-05 | Unisys Corporation | Heat transfer module incorporating liquid metal squeezed from a compliant body |
US5561590A (en) * | 1995-09-21 | 1996-10-01 | Unisys Corporation | Heat transfer sub-assembly incorporating liquid metal surrounded by a seal ring |
US5745344A (en) * | 1995-11-06 | 1998-04-28 | International Business Machines Corporation | Heat dissipation apparatus and method for attaching a heat dissipation apparatus to an electronic device |
US5611884A (en) * | 1995-12-11 | 1997-03-18 | Dow Corning Corporation | Flip chip silicone pressure sensitive conductive adhesive |
US5720100A (en) * | 1995-12-29 | 1998-02-24 | Motorola, Inc. | Assembly having a frame embedded in a polymeric encapsulant and method for forming same |
US5808874A (en) * | 1996-05-02 | 1998-09-15 | Tessera, Inc. | Microelectronic connections with liquid conductive elements |
JP2830852B2 (en) * | 1996-08-08 | 1998-12-02 | 松下電器産業株式会社 | Electronic component mounting method |
US5975408A (en) * | 1997-10-23 | 1999-11-02 | Lucent Technologies Inc. | Solder bonding of electrical components |
US6114181A (en) * | 1998-08-05 | 2000-09-05 | International Business Machines Corporation | Pre burn-in thermal bump card attach simulation to enhance reliability |
-
1996
- 1996-05-02 US US08/641,698 patent/US5808874A/en not_active Expired - Lifetime
-
1997
- 1997-05-01 WO PCT/US1997/007229 patent/WO1997040958A1/en active Application Filing
- 1997-05-01 AU AU29286/97A patent/AU2928697A/en not_active Abandoned
- 1997-11-03 US US08/962,693 patent/US6202298B1/en not_active Expired - Lifetime
-
1998
- 1998-03-31 US US09/052,721 patent/US6096574A/en not_active Expired - Lifetime
-
1999
- 1999-05-04 US US09/305,028 patent/US6238938B1/en not_active Expired - Lifetime
-
2001
- 2001-01-10 US US09/757,897 patent/US6437240B2/en not_active Expired - Lifetime
-
2002
- 2002-05-15 US US10/146,353 patent/US6846700B2/en not_active Expired - Fee Related
-
2003
- 2003-02-21 US US10/371,324 patent/US6774306B2/en not_active Expired - Lifetime
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Also Published As
Publication number | Publication date |
---|---|
US6096574A (en) | 2000-08-01 |
US6238938B1 (en) | 2001-05-29 |
US6202298B1 (en) | 2001-03-20 |
US5808874A (en) | 1998-09-15 |
US6846700B2 (en) | 2005-01-25 |
US20020166688A1 (en) | 2002-11-14 |
AU2928697A (en) | 1997-11-19 |
WO1997040958A1 (en) | 1997-11-06 |
US20030150635A1 (en) | 2003-08-14 |
US6774306B2 (en) | 2004-08-10 |
US6437240B2 (en) | 2002-08-20 |
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